An odd occurrence has been spotted by an increasing number of iPhone users - their Apple ID accounts are being locked. This would normally happen if someone attempts to access an ID by entering an incorrect password too many times, but that's not the case here. It's still unclear what is prompting Apple's systems to lock people's accounts, but if that happens to you the company will require you to reset your password. It's an inconvenience, for sure, but thankfully you aren't being permanently locked out of your account. You'll instantly know if you're affected because iOS will...
Source: https://www.gsmarena.com/some_iphone_users_are_getting_their_apple_id_accounts_locked-news-34202.php