Disabling function with event hub trigger does not prevent binding resolution when disable setting uses underscores

Azure function app on .net 8 isolated tries to resolve a disabled function's EventHubTrigger binding. We do not have a valid event hub to connect to this listener for this environment at this time. This causes repeated `The listener for function 'Functions.' was unable to start.` errors

#### Investigative information

Please provide the following:

- Timestamp: 2026-08-20T15:50:16.8188985Z
- Function App version: v4
- Invocation ID: (not available on this trace, but if it helps app id is `ade49550-b1eb-46a4-b8e3-493f4163d827`)
- Region: West US 2

#### Repro steps

Trigger like the following (using placeholders):
```csharp
[Function(nameof(HandleEvents))]
public async Task HandleEvents(
[EventHubTrigger(
"foobar",
Connection = "MyEH",
IsBatched = false,
ConsumerGroup = "MyConsumerGroup"
)]
EventData message
)
```

app settings in az portal like:

```
{
"name": "AzureWebJobs__HandleEvents__Disabled",
"value": "true",
"slotSetting": true
},
{
"name": "MyEH__fullyQualifiedNamespace",
"value": "default",
"slotSetting": false
},
```

_note: no app slots in use in this solution._

#### Expected behavior

No exception thrown, no error logs

#### Actual behavior
Logs:
> The listener for function 'Functions.HandleEvents' was unable to start.

> Retrying to start listener for function 'Functions.HandleEvents' (Attempt 548)

Exception:

> Microsoft.Azure.WebJobs.Host.Listeners.FunctionListenerException
> at Microsoft.Azure.WebJobs.Host.Listeners.FunctionListener+d__13.MoveNext

full stacktrace:
```
Microsoft.Azure.WebJobs.Host.Listeners.FunctionListenerException:
System.AggregateException:
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Primitives.EventProcessor`1+d__95.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Primitives.EventProcessor`1+d__69.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.WebJobs.EventHubs.Processor.EventProcessorHost+d__16.MoveNext (Microsoft.Azure.WebJobs.Extensions.EventHubs, Version=6.5.2.0, Culture=neutral, PublicKeyToken=014045d636e89289)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.WebJobs.EventHubs.Listeners.EventHubListener+d__17.MoveNext (Microsoft.Azure.WebJobs.Extensions.EventHubs, Version=6.5.2.0, Culture=neutral, PublicKeyToken=014045d636e89289)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.WebJobs.Host.Listeners.FunctionListener+d__13.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.46.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: /_/src/Microsoft.Azure.WebJobs.Host/Listeners/FunctionListener.cs:68)
Inner exception System.Net.Sockets.SocketException handled at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw:
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.AsyncResult.End (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at Microsoft.Azure.Amqp.Transport.AmqpTransportInitiator+<>c.b__17_1 (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Amqp.AmqpConnectionScope+d__81.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.FaultTolerantAmqpObject`1+d__6.MoveNext (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.Singleton`1+d__24.MoveNext (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.Singleton`1+d__24.MoveNext (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Amqp.AmqpConnectionScope+d__77.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Amqp.AmqpClient+d__35.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Amqp.AmqpClient+d__35.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.FaultTolerantAmqpObject`1+d__6.MoveNext (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.Singleton`1+d__24.MoveNext (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.Amqp.Singleton`1+d__24.MoveNext (Microsoft.Azure.Amqp, Version=2.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Amqp.AmqpClient+d__30.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Amqp.AmqpClient+d__30.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.EventHubConnection+d__37.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Primitives.EventProcessor`1+d__103.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Primitives.EventProcessor`1+d__103.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Azure.Messaging.EventHubs.Primitives.EventProcessor`1+d__81.MoveNext (Azure.Messaging.EventHubs, Version=5.12.2.0, Culture=neutral, PublicKeyToken=92742159e12e44c8)

```

#### Known workarounds

I _could_ try to provide a fake event hub that actually exists but I don't want to if i don't have to.

#### Related information
n/a

Reproduce the issue with the shown C# EventHubTrigger and AzureWebJobs__HandleEvents__Disabled setting, then trace function disable-setting resolution through the host before EventHubListener startup. Verify that an underscore-form setting prevents listener creation and repeated connection errors for the disabled function, while enabled functions retain their existing behavior.

Written by the indexing model from the issue text.