Outlook 365 New Mail Icon in Task Bar Does Not Turn Off After Running Permanent Delete Rule

Here's the problem:

1. New mail icon in task bar turns on when mail arrives.
2. A permanent delete rule executes which deletes the unwanted mail almost instantly.
3. The new mail icon remains on even though there is no longer any new mail to read.
4. I can clear the new mail indication by clicking on the first mail item in the Outlook mail list.

I depend heavily on this feature so I don't want to disable it.  I believe this is a bug.

Peter