I used to be SR 27, and I had 15000 req points, now it’s all gone. My multiplayer service record (Arena and Warzone) has also been wiped clean. I also can’t connect to a match. Is there a fix for this?
You’re not the only one, other People on the Forums are saying the same thing. I just found out that it happened to me too. 
ME too!!! half an hour ago… all gone!!! 343 do something!!!
Thanks for the report! We’re aware of this and investigating.
You can continue to check on the status of all Halo 5: Guardians services: aka.ms/H5Status
Please use this thread if you have any further reports: https://www.halowaypoint.com/en-us/forums/e0d9938206f04a598ce84f2c8cadce02/topics/my-multiplayer-progress-has-been-reset/9e8d9526-84e8-40d3-b699-f4bd5857f320/posts
We apologize for the inconvenience.