Welp I finally got to play Halo campaign co-op and turns out it's completely broken, it's apparently impossible to get less than 100 ms ping and when trying to play with a friend from South America it just completely freezes for player 2 after a while 💀
דגל שכור 🏴 
@thufie Now we're gonna try Firefight and hope it doesn't use the same netcode (I suggested regular multiplayer originally but she doesn't like PvP)
@hazelnot the regular multiplayer actually works on LAN at least. Good luck!
@thufie Thanks 😭
@thufie Update: Firefight works :P
@thufie It is 😔