Sharing this in case others are also having the issue, but apparently 1Password (npub1ak3…t4td) can somtimes interfere with the #MacOS #emoji selector!
I have had this issue off and on for quite some time, but quitting the app did really seem to resolve it in this instance.
https://discussions.apple.com/thread/256296303?answerId=262043872022&sortBy=rank#262043872022