I don't always answer personally!
I can't answer your question directly because I don't have Windows 11 on my development system...I'll try to see what I can do!
mGalaxy has not been abandoned at all...here are the features of the new version and some screenshots of 2 new themes (one was already available on the MacOSX version):
⦁ [New] mGalaxy_Runway: missing RetroArch cores can be downloaded directly from the mGalaxy_Runway interface.
⦁ [New] mGalaxy_Runway: sort on 'most played' in the database.
⦁ [New] 'Presenter 3' theme.
⦁ [New] 'Tiles' theme.
⦁ [Improved] Redesigned 'System selection' panel interface.
⦁ [New] Integration of the
https://retroachievements.org/ achievement system.
⦁ [Improved] Redesigned 'Top 10' panel interface showing the games most played by users and the community.
⦁ [Improved] Controllers manager extends to all controllers (before: just the first 2 ones)