I received an email stating someone used my account to sign into an iPhone 12….
Why am I receiving issues regarding my Apple ID
iPhone 11, iOS 14
Check your device list to see if there is a device signed in that you don't recognize. You can remove the device using the steps in the article below. As a precaution, change your password.
Apple ID device list -Check to see where you‘re signed in. *
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.