Can I ask few things when you created the new profile to test. 1. What window did you open and test, is it Control Panel windows, File Explorer windows, or all desktop applications?
- When the windows opens check you mentioned it's on maximized, can you click the Restore Down button (the middle button between Minimize and Close), does the window shrink?
- If you resize a window manually and close it, does it reopen maximized the next time?