HALO 4 NO XP for CHALLENGES OR gameplay

sorry maybe this has been answered many times or asked but didnt see any threads and a little bit of googling didnt bring much up … but i been playing halo 4 for a little while i just leveled up to 50 but today as i was playing i did a few challenges and i was not recieving any xp for anything not even just the basic xp for playing spartan ops find a game i tried war games everytime the game finishes takes me back to the lobby …is this a known glitch?

Did you choose a specialization class thing if not you will not get anymore xp.

edit: for the lobby thing the only thing I can think of is everyone left or something but mostly don’t know.

It might be what Crazywilliam suggested, you have to choose a specialization after ranking up to 50. If it’s not that, it might be this: https://forums.halowaypoint.com/yaf_postst191528_Whats-up-with-servers.aspx