Unicode input doesn't show u underlined

[flo2k]

Hello everyone,

I just recognised on my system Linux Mint Mate 20.1 Ulyssa (updated from previous versions) that with my user account, the unicode input is not fully working:
- When I press <Control><Shitft>u I was supposed to see the underline u and then I can input my unicode codepoint.
- But on my system, the underline u ist not shown.
- However, the input of a unicode codepoint still works and it is inserting the unicode character correctly. But the missing underline u is somehow strange.

I tested different terminals, xed, as well as LibreOffice writer - everywhere the same problem.

I also tested a different user profile on the same system, in which everything works fine. In viewtopic.php?f=206&t=327425&p=1959815& ... e#p1959815 there was suggested to create a new user profile, and copy the required files into that new profile. But I would like to keep my profile, it's evolved over the years with many different settings.

- How can I diagnose what causes the missing underline u?
- What could be the problem in my profile?
- What part (program, library, font) is responsible for drawing the underline u?

Best,

flo2k