This is going to be a long winded one, apologies in advance!
Yesterday, I helped some people with the Deja Vu achievement on ODST. We got near to the end of the highway when my screen went black. I was then taken to the Xbox dashboard. When I reopened MCC, I was back in the game but could not move and had main menu features over my HUD (Nameplate and rank in top right, toggle for text chat etc. in the bottom left.)
The other players checked the session leaderboards and it still said that I was in the game. We therefore decided that as we were close to the end of the level, they would continue with me being stationary. This worked, they got the achievement and when they got back into the lobby, my nameplate kept disappearing and reappearing from the lobby.
MCC, for me at this point, crashed. I had to restart/power cycle several times just to get it to start up again.
Later in the evening, another friend and I attempted H2 Cairo Station on the LASO Playlist. Finally finished it after 5 hours. When we were loading into Outskirts, my friend had the Outskirts loading screen whereas I had a Cairo Station loading screen followed by the classic H2 blue connection screen.
After this, Outskirts loaded and we continued to the first checkpoint before my friend (the host) ended the game.
When back in the lobby, his playlist said he had 3/15 completed (Opening cinematic, Armoury and Cairo). When I checked mine, it said I had only completed the cinematic and Armoury and was only able to resume the playlist from Cairo Station.
Further to this, it now appears that I no longer have any MCC data whatsoever on Halo Waypoint. Instead I am now greeted with “Problem detected. Well, this is embarrassing. Looks like we have some problems on our end.”
Honestly no idea what on earth has happened to my MCC data and a bit worried that all progress going forward isn’t going to count. All of this happened within the space of 8 or so hours.