FUNCTIONS_WORKER_RUNTIME dotnet-isolated can't be changed

#### Investigative information

Please provide the following:

- Timestamp: 2025-03-05 09:50:10 CET
- Function App version: Microsoft.Web/sites@2024-04-01
- Function App name: n-qa-bannerdata-func
- Function name(s) (as appropriate):
- Invocation ID:
- Region: swedencentral

#### Repro steps

Provide the steps required to reproduce the problem:

1. Deploy a function app with FUNCTION_WORKER_RUNTIME='dotnet-isolated'
2. Change to 'dotnet'
3. Unable to get rid of the warning that the function app requires 'dotnet'
4. Redeploy the function app with a new name to circumvent the issue is the only possibility.

#### Expected behavior

To be able to change from dotnet-isolated to dotnet.

#### Actual behavior
Even after changing to dotnet we get the below error:



#### Known workarounds

Redeploy the function app with a different name. Redeploying with same name will cause the issue to persist.

#### Related information

Source

module functionApp 'br/public:avm/res/web/site:0.15.0' = {
name: 'functionApp-${uniqueString('functionApp', deployment().name)}'
scope: resourceGroup(resourceGroupConfiguration.name)
params: {
kind: 'functionapp,linux'
name: functionAppConfiguration.name
serverFarmResourceId: serverFarm.outputs.resourceId
appSettingsKeyValuePairs: {
AzureFunctionsJobHost__logging__logLevel__default: 'Trace'
FUNCTIONS_EXTENSION_VERSION: '~4'
FUNCTIONS_WORKER_RUNTIME: 'dotnet'
}
siteConfig: {
appSettings: union(
[
{
name: 'FUNCTIONS_INPROC_NET8_ENABLED'
value: '1'
}
{
name: 'APPINSIGHTS_INSTRUMENTATIONKEY'
value: applicationInsights.outputs.instrumentationKey
}
{
name: 'WEBSITE_RUN_FROM_PACKAGE'
value: '1'
}
{
name: 'WEBSITE_WEBDEPLOY_USE_SCM'
value: 'false'
}
{
name: 'AzureWebJobsStorage'
value: 'DefaultEndpointsProtocol=https;AccountName=${sa.outputs.name};EndpointSuffix=${environment().suffixes.storage};AccountKey=${existingStorageAccount.listKeys().keys[0].value}'
}
{
name: 'WEBSITE_CONTENTAZUREFILECONNECTIONSTRING'
value: 'DefaultEndpointsProtocol=https;AccountName=${sa.outputs.name};EndpointSuffix=${environment().suffixes.storage};AccountKey=${existingStorageAccount.listKeys().keys[0].value}'
}
{
name: 'WEBSITE_CONTENTSHARE'
value: toLower(functionAppConfiguration.name)
}
],
functionAppConfiguration.additionalAppsettings ?? []
)
netFrameworkVersion: '8.0'
ftpsState: 'FtpsOnly'
minTlsVersion: '1.2'
alwaysOn: true
ipSecurityRestrictions: ipSecurityRestrictions
}
httpsOnly: true
virtualNetworkSubnetId: subnet.outputs.subnet.resourceId
managedIdentities: {
systemAssigned: true
userAssignedResourceIds: [
uami.outputs.resourceId
]
}
roleAssignments: [
{
principalId: uami.outputs.principalId
roleDefinitionIdOrName: 'de139f84-1756-47ae-9be6-808fbbe84772' // Website Contributor
}
{
principalId: uami.outputs.principalId
roleDefinitionIdOrName: '4633458b-17de-408a-b874-0445c86b69e6' // Key Vault Secrets User
}
]
storageAccountResourceId: sa.outputs.resourceId
storageAccountUseIdentityAuthentication: false
vnetRouteAllEnabled: true
appInsightResourceId: applicationInsights.outputs.resourceId
}
dependsOn: [rg]
}