[KevinH]

I read a bit up on Stage Manger and according to the docs it can group two or more apps to the same screen/Desktop. So maybe given your full-screen setup, Stage Manager might help.

FWIW with either the Ctrl or Options buttons help down, clicking the green button should convert it to Maximizing an app Window which grows it as big as it can be without using Full Screen mode. Maybe when maximizing instead of full screen you can get things to work together better. Again, these are things I never use as I do not want to ever track down an App I open.