I get a similar problem. I double click on the notification, and yes it does bring up the notified email but hidden behind all my other windows.
This is not terminal, just very annoying for workflow. I first thought nothing was happening but then on close down found all these windows waiting. When I double click I want to deal with that now not have it appear as a background window.
It always used to bring that email to the front for immediate action.
Is there some setting for this? If it's a bug can it be fixed.
I'm using the latest updated version of Microsoft 365 on a year old MS Surface top of the range laptop with the latest Windows OS