Setting shortcut for Safari extension challenges

Hello!

For years, I had cmd-# as the Safari extension shortcut for 1Password. Some time ago, it stopped working. Strangely, when I try to set it to cmd-# in the Safari extension, what is used is actually cmd-c which, obviously, isn't really optimal as it interferes with the Copy shortcut.

This is on macOS (latest system and 1Password). I have my System language set to German and am using a German keyboard. Anything I'm doing wrong or can do differently? It would be great to get back to the ease of cmd-#!

Thanks for any help or suggestions!
Peter