Must enter login password twice!
When I login, I put in my password and it jiggles as if I have input it incorrectly. I repeat the process and I login smoothly. Now, when I first bought the iMac, I put this down to my human error but it happens every day so it is now another iMac quirk or a 'security' measure.
This behaviour only happens when I login. When I signed into this forum, it all worked smoothly first time.
iMac 21.5″, macOS 11.1