This might help with the debugging. The problem seems to have followed (originated?) into my chrome browser too. I found this website that list the problem: windows 10 - Chrome Maximize button greyed out and not working - Super User
Using somewhat the same method:
- Open Brave
- Enter
brave://flags
in the address bar - Search for “Touch UI Layout”
- Set Touch UI Layout to disabled
I was able to get it to reappear without the reinstall and cleaning.