NCan you post the verbose logs? LLDAP_VERBOSE=true
NIt's interesting that you get a different error from trying with the correct password than with a wrong one (did I understand that correctly?)
NAlthough yeah, it says "login successful for admin", that's about all we need to know
NCan you see if there's an error in your browser in the console? Open it with f12 and then try to log in.
NYou can try to log in via the command line with ldapsearch, but I expect that would work
NYou could open the LLDAP http port directly (instead of going through your proxy) to see if that works
NThat could indicate a proxy error
NIf it's a frontend problem, you could try incognito mode (or clearing the cache and cookies)
NCan you try in incognito?
NI'm sorry to say I can't diagnose a non-existent problem 
NNo, time doesn't help
NYou're welcome!
NIt could be that the frontend was in a bad state with an invalid JWT and then it tried to log in again because the 24h had passed?
NWild guess
NCould be
NRight. Well, glad you got it working!