Function startup error: "Access to the path '/home/site/wwwroot' is denied. Permission denied"

We're using Java (Spring-Boot) functions in Premium-Plan. After triggering the function with http we occasionally see following error before entering the function code

`
Access to the path '/home/site/wwwroot' is denied. Permission denied
A host error has occurred during startup operation '9a0b8cf7-a7e0-4745-b43b-bbb0f7e78c3a'.
`

Call Stack
`System.UnauthorizedAccessException:
at System.IO.FileSystem.CreateDirectory (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.IO.Directory.CreateDirectory (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.IO.Abstractions.DirectoryWrapper.CreateDirectory (System.IO.Abstractions, Version=2.1.0.227, Culture=neutral, PublicKeyToken=96bf224d23c43e59)
at Microsoft.Azure.WebJobs.Script.FileUtility.EnsureDirectoryExists (Microsoft.Azure.WebJobs.Script, Version=4.5.0.0, Culture=neutral, PublicKeyToken=null: /src/azure-functions-host/src/WebJobs.Script/Extensions/FileUtility.cs:38)
at Microsoft.Azure.WebJobs.Script.ScriptHost.InitializeFileSystem (Microsoft.Azure.WebJobs.Script, Version=4.5.0.0, Culture=neutral, PublicKeyToken=null: /src/azure-functions-host/src/WebJobs.Script/Host/ScriptHost.cs:478)
at Microsoft.Azure.WebJobs.Script.ScriptHost.PreInitialize (Microsoft.Azure.WebJobs.Script, Version=4.5.0.0, Culture=neutral, PublicKeyToken=null: /src/azure-functions-host/src/WebJobs.Script/Host/ScriptHost.cs:468)
at Microsoft.Azure.WebJobs.Script.ScriptHost+d__94.MoveNext (Microsoft.Azure.WebJobs.Script, Version=4.5.0.0, Culture=neutral, PublicKeyToken=null: /src/azure-functions-host/src/WebJobs.Script/Host/ScriptHost.cs:277)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.WebJobs.Script.ScriptHost+d__93.MoveNext (Microsoft.Azure.WebJobs.Script, Version=4.5.0.0, Culture=neutral, PublicKeyToken=null: /src/azure-functions-host/src/WebJobs.Script/Host/ScriptHost.cs:258)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Extensions.Hosting.Internal.Host+d__12.MoveNext (Microsoft.Extensions.Hosting, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.Azure.WebJobs.Script.WebHost.WebJobsScriptHostService+d__52.MoveNext (Microsoft.Azure.WebJobs.Script.WebHost, Version=4.5.0.0, Culture=neutral, PublicKeyToken=null: /src/azure-functions-host/src/WebJobs.Script.WebHost/WebJobsScriptHostService.cs:310)
Inner exception System.IO.IOException handled at System.IO.FileSystem.CreateDirectory:`

It might have something to do with maxConcurrentRequests beeing set. Here is the host.json file:

`{
"version": "2.0",
"functionTimeout": "00:10:00",
"extensionBundle": {
"id": "Microsoft.Azure.Functions.ExtensionBundle",
"version": "[3.3.0, 4.0.0)"
},
"extensions": {
"http": {
"routePrefix": "api",
"maxOutstandingRequests": 200,
"maxConcurrentRequests": 1,
"dynamicThrottlesEnabled": true
}
}
}`

Same error occurs on Python Function with the following host.json:

`{
"version": "2.0",
"functionTimeout": "00:20:00",
"logging": {
"applicationInsights": {
"samplingSettings": {
"isEnabled": true,
"excludedTypes": "Request"
}
}
},
"extensionBundle": {
"id": "Microsoft.Azure.Functions.ExtensionBundle",
"version": "[2.*, 3.0.0)"
},
"extensions": {
"serviceBus": {
"messageHandlerOptions": {
"maxConcurrentCalls": 1
}
}
}
}
`