It’s actually come to my attention that a lot of people have been having this problem. It seems that as of January 10th 2019, the ‘you’re joking’ achievement is glitched. I’m really hoping this problem gets fixed soon.
My current times on all the halo 4 missions add up to about 170 mins, so I’m definitely under the 3 hour mark.
I’ve also checked on halo waypoint, all my speedrun times are the same. All the detail is there, but nothing is popping. Ive tried everything, restarting the game, opening and closing the achievements on service record, etc.
This kinda thing is out of my hands so I really hope this can be fixed. The last recorded person getting this achievement was over a month ago now, and I know I’m not the only one having this issue.