Loss of XP/ XP not registering?

I have been playing H4 again and I have been loving it. I have been grinding XP… doing all the challenges and just playing in general. Yesterday I got to SR-59 and getting pretty close to finishing my first specialization only to log in today and I am back to SR-58 and over 20,000 XP short of SR-59. What gives? It says I completed all the challenges and the Monthly Challenge too. I figure I am about 30,000 XP short of where I ended yesterday. I would really like that XP back. Anyone have similar issues?

Has happened to me a few times.
Once after completing a achievement it didn’t add any xp but showed the achievement as completed. The other times it registered causing me to level up , unlock new stuff and whatnot but when returning to the game the next day I would find that it had been taken away and I had gone down a level and lost all my new stuff.
I was pretty pissed off at the time but since reaching max rank I’m glad it won’t happen to me again.
Not sure what causes it . It’s not like I pulled the plug to my Xbox the moment the xp went through ,causing some error to take it away again.
so yea, you aren’t the only one and there are a few other threads around with the same/similar issues.

After a recent Griff ball match, NONE of the players received any xp.

It sux, but I guess this just happens sometimes