I have one user on my forum who has had intermittent issues with being able to login. The member joined in January 2018 and had no issues at first. The issues appeared a few months ago, resolved, and have now returned.
I'm running phpbb 3.2.5 with PHP 5.4 (due to another part of my website needing an older version of php).
The forum user who's having issues has tried logging into the site via his computer (running Win 10) and his phone, but when he tries to log in, it says he has the wrong password. At that point, he tries the Forgot Password link, but it tells him his email address isn't associated with the forum or account.
I've tried manually resetting his password and have double checked his email address. Resetting the password worked before, but not this time. When I try logging in with his credentials, I have no problems.