This happens to me too, I’m using 1Password. I have a suspicion the plug-in is involved with this but I’ve not had time to collect evidence yet. Seems to be rare though, I’ve not spotted anybody else with this issue.
This makes me realise how much of a pain it has been to use in the past weeks or so. Now that it is back to normal snappy it is such a pleasure to work with again.
It is my only issue with M1.