Recently since last week certain windows are opening in full screen instead of their normal size on my ROG Ally, I did recently set up using another laptop as a bigger display and I installed spacedesk but haven’t used that yet. It’s not everything, but most notably installers, 7zip “extract files” windows and additional applications from plugins from the museum in AZ. Is this a bug or something that needs an update or is it related to external display settings or did something I get from the museum mess up window sizes because it really only started after I had installed Ableton Live

 

Generally;
Win 7, 8, 10, 11 - pretty much everything since winXP, does not remember desktop window sizes/positions. If you want XP type window positioning on later systems you'll need to use something like "window manger".