User is unable to login after password reset and getting "could not authenticate you from ldapmain due to invalid credentials" error.

User had reset his LDAP user ID password and then try to login gitlab but unfortunately he could not able to login and it giving below error" could not authenticate you from ldapmain due to invalid credientials". I have checked application logs there it said it was "user is locked" and we requested him to reset again password and try ,for the first time it worked and agin he got the same error. May I know what is the issue and could you please help asap. Thank you.