Bypass for the Alt-Tab Problem on Windows 11.
Pressing Alt (Right or Left) will make the game go to windowed mode before the switch application. It's not the complete solution yet but should avoid the annoying situation of having the game in background restoring it. Pressing again Alt with the focus on the game will restore the fullscreen.
I will try to find a better solution asap.
Thanks to "The Obtuse Rubber Goose" to spot the problem.