Resolved Sonoma Notification Center behavior for Mail - open new message in standalone window or switch to app, can't resolve

[BeatCrazy]

I think this is related to Sonoma, but not sure?

I have two Macs, both running 14.2.1 and Apple Mail. When I get a new email, I receive a Notification Center notification. I am using Stage Manager.

When I click on the message preview in Notification Center, I get two different behaviors, depending on the Mac:
A) New mail message opens up in its own tab on top of my current application, i.e. Safari (good)
B) New mail message opens up in its own tab and forces the Mail application with the separate message tab as the main Stage Manager app (bad)

All my settings for Stage Manager and Notifications are the same between the two machines, as best I can tell!

 

[BeatCrazy]

Solved.

Turns out you need to have Mail grouped within the Stage Manager grouping if you don't want it to take over as its own application when you click on a notification.

So the behavior was the same the whole time, but machine A had Mail grouped in the same Stage as my other applications.