Hi @svh - I used my ex-CSM superpowers  to see if I can replicate the problems you’re describing in your community, and I couldn’t.  In your control environment the More options drop-down works fine for me, and the same with the Theme option on your front-end (lovely looking community btw!).  

This suggests to me that the issue is likely to be something local to your computer.  It’s interesting that it’s impacting both Chrome and Safari.  Have you tried rebooting your computer?  Do your colleagues have the same problem?  If the problem continues I’m afraid I need to ask you to create a ticket for our Support team - they will surely have more tips and ideas.

Thank you @Kenneth R! It works again now without any reboot or other action. Maybe I just needed to go to lunch  

Ah that’s good to hear.  Always a good idea to go get lunch when you’re stuck with a problem.  :)