Azure Functions PUT HTTP trigger endpoint not triggered

Question

I have HTTP trigger endpoint defined:

   {  
     "generatedBy": "Microsoft.NET.Sdk.Functions-3.0.11",  
     "configurationSource": "attributes",  
     "bindings": [  
       {  
         "type": "httpTrigger",  
         "route": "{driverId}",  
         "methods": [  
           "post",  
           "put"  
         ],  
         "authLevel": "function",  
         "name": "reqeust"  
       }  
     ],  
     "disabled": false,  
     "scriptFile": "whatever.dll",  
     "entryPoint": "Whatever.PutDriverFunction.Run"  
   }  

When I Run POST method everything is OK. 400 is due to empty body:

So instead of POST I use PUT - same function key, body, route params, headers, etc:

No actual code defined is triggerd, nothing appears in Application Instights, just like it was not triggered at all.
There is no difference in request handling in code based on verbs. When I run locally everything works fine.
The PUT has been working for some time until recently.

The both above used master key, if I change to any other key than master, POST still works OK.
But PUT behaves totally wierd.
When function key is used response is 401
When host key is used response is 403.

Is this a bug/change in runtime or something that I'm doing wrong, that PUT does not work as expected?

Answer 1

@Filip Zan @Chris Whiting @roger chang @Tim Myers

Apology for the delay and any inconvenience with this issue. The product team has updated the code to fix this issue: https://github.com/Azure/azure-functions-host/pull/7270 and the fix will start deploying soon.

You can watch the app service announcement repo to receive notification about new version releases: https://github.com/Azure/app-service-announcements/issues

The workaround would be to pin it to version 3.0.15406: https://learn.microsoft.com/en-us/azure/azure-functions/functions-app-settings#functions_extension_version