So me and my fiance live together we have been playing coop we are on Halo 2 the missions have been counting as complete for me and here until Regret she is not getting any achievements and it doesn’t show on her stats that she completed it. Me and her are doing a run through on Legendary so its not so simple to just redo the levels. This is so damn irritating and this is her first experience with Halo and we got through CE just fine and what sucks we got all the way to Uprising and realized it stopped tracking at Regret and this is stopping her from wanting to even play now. Don’t tell we got to go through all that BS again because no offense Halo 2 is a f*cking nightmare on Legendary.
Exact same happened to me and my friend. We were doing our Halo 2 Legendary run. The missions were counting as complete for me but not my friend. Note that I was always the party leader. We only realized this after we completed “The Great Journey” and I got the achievement for completing the campaign on legendary, but my friend did not. After my friend looked at all of the missions in the menu, legendary completion stopping counting for him after “The Arbiter”. We are starting out Halo 3 legendary run soon and will see if this is a Halo 2 only bug or not. I will edit this and verify whether or not if completion counts for my friend on Halo 3 after we beat the first couple of levels.
As a tip, my friend and I are thinking about replaying the campaign for Halo 2 on legendary with him as the party leader so he gets the completion as well. We are going to use a bunch of skulls to make it easier as well as doing speedrun section skips to make the process faster and more tolerable.