Hmm. I am running 10.6.9-mac-mas-public (458440) Editor: v116.1.14913 Service: v1.26.7
This is on macOS Big Sur 11.1.
The command-tilde works in all other apps EXCEPT Evernote. (yes, I am using Evernote in "Normal" view.)
Peter, did you do any other config changes that might influence this?