Hi @Grmacjon-MSFT ,
Thank you for your response.
As this issue is intermittent, the following answers are based on the last two times I have seen this.
Do you face the same behaviour when using PowerShell or Azure CLI to remove the RG?
Yes same issue with both CLI and PS. The delete starts but never ends. Both the times the (desktop not pscore) PowerShell prompt just sat there doing nothing. Hitting Ctrl+C also did not end the process. Had to close the windows terminal tab.
Double-check to see if there are any ‘Locks” added to your App Service Plan and RG.
There were no locks present at all. I did not remove any locks before deleting after 'resetting the slot configuration'.
If there are any existing apps and configured with multiple slots, ensure that the slots are deleted prior to deleting the apps/RG.
In both the cases I have seen this recently, there was only one app service plan, one function app and a staging slot for that app. I could not delete any of these resources in any order until the slot configuration reset, possibly because I had triggered resource group deletion first and it would not finish. After the reset, I deleted staging slot, then app and then app service plan. Didn't try any other combination.
Hope this helps. Either way, if the engineering team can explain why the workaround works, it would be useful as well.