contacts disappearing

I have this exact problem as well. Started in mid-January 2022. Contacts disappear one at a time. I use my iCloud account for contacts and confirmed that the contacts toggle is off for other mail accounts. Nobody else is using that iCloud account for contacts. I was able to recover contacts from a backup and that seemed to help, until today when I see that I've lost a few more.

Contacts are tied to email accounts. So if you share an email account with someone and they delete a contact from their device it will also be deleted from yours.

What kind of email account is it (e.g., AOL, Verizon, iCloud, etc)?