Apple id
Someone keeps logging in to my Apple ID after I’ve changed my password 3 times in 3 days.
iPhone 8 Plus, iOS 13
You can also add 2 Factor Authentication to your account for more security. If the attempts continue, you might want to consider a name change.
Link to contact Apple Support in the article.
Note the restrictions in the article.
What to do after you change your Apple ID or password - Apple Support I suggest doing this before you change your Apple ID or password.
Apple ID -Two-factor authentication
Two Factor Authentification availability
Apple ID - Using app-specific passwords
Apple ID - Two Step Verification App Specific Passwords