Whenever I load a campaign mission in Halo CE, there is a black screen with the cursor on it for around 30 seconds and then the mission loads normally. It only happens on CE and makes playing co op impossible due to the differences in load times bug.
EDIT: I should add that I had played co op for three missions before this load time bug started and now it does it on every CE mission load.
So I was able to solve my issue with the advice listed here https://www.reddit.com/r/halo/comments/n1cxtt/halo_ce_mcc_pc_severely_delayed_loading_screens/
Long story short, unplugging the second USB cord from my Corsair keyboard solved the issue. Thought I’d follow up in case anyone else happened upon this post.