Answer
Locked (TIMED) specifically means the number of failed login/password attempts has exceeded the 'Failed Login Attempts' threshold defined on the Oracle Profile assigned to that user — check the user's assigned profile and that specific property value first. Adjusting the threshold can reduce how often it locks, but the more important thing is finding why failed attempts keep happening in the first place: either someone is actually trying to guess that user's password, or (more commonly) some other integration or third-party application is configured with old/incorrect credentials for that account and is repeatedly retrying, tripping the lockout each time — tracking down and correcting whichever process holds the stale credentials resolves the recurring lockouts at the source.