A buddy and I have beat every halo in a row on legendary with no problems, except halo 2, we saved that for last because of the forced restart to a checkpoint when one person dies. When we finally get to halo 2 we get as far as Oracle when we decide to take a break. We both check our progress and it turns out that the host (me) only had the legendary coop status count and my friend did not. 343 please look into this as there have been other posts talking about this bug. We are both on Xbox one.
I am also having this issue. My friend hosted and we played to the arbiter and he has the legendary completion but I do not.
I had a similar issue with it, had to got back on solo legendary to finish the job.
Looks like the cinematic causes connection issues
Me and my friend had the exact same problem in the same spot. So stupid.
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> Me and my friend had the exact same problem in the same spot. So stupid.
I’m the friend. It’s true.
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> > 2535459937867271;4:
> > Me and my friend had the exact same problem in the same spot. So stupid.
>
> I’m the friend. It’s true.
Verified
Same here. As of August 7th 2020 to August 10th 2020, I completed the entirety of Halo 2 Legendary campaign COOP and it didn’t give me progress but gave it entirely to my friend who was the host. I was able to get achievements for collecting skulls and collecting all the toys but not completing the missions 
I’ve played the entire Halo 2 campaign with my wife on legendary and I noticed some of the missions showed that we only completed them on normal, we just played metropolis and gravemind and they still dont show legendary completion.
It’s ridiculous. I just played up to the The arbiter. My brother hosted us 1st and it gave him all the legendary credit and it said I have completed nothing. Then later on I hosted and my buddy joined to see if we could remedy the issue. Starting from the beginning we played up thru delta halo and I got the credit and he got 0. It’s like they are playing a joke on us.
The list of bugs is pretty big, but 343 never read this forum. I think it exists so that players can try and help each other solve problems? In any case I am not aware of any fix, it’s in their ballpark.
Would they prefer we reported these bugs over on their support site? It would be nice to have some clarification as to if there’s any point whatsoever to posting in this forum, because I’ve used it half a dozen times and never once received any sort of acknowledgement or response from the devs or their community staff. The only people who have responded have been forum volunteer monitors.
Missions not counting as done is common, I’ve had it many times in Reach. I also still don’t have Steam credit for beating Halo 3 LASO. I just… it’s so depressing and frustrating that there’s so little communication between them and us. Makes us feel like they simply don’t care and we’re posting this stuff for a laugh or something.
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> The list of bugs is pretty big, but 343 never read this forum. I think it exists so that players can try and help each other solve problems? In any case I am not aware of any fix, it’s in their ballpark.
>
> Would they prefer we reported these bugs over on their support site? It would be nice to have some clarification as to if there’s any point whatsoever to posting in this forum, because I’ve used it half a dozen times and never once received any sort of acknowledgement or response from the devs or their community staff. The only people who have responded have been forum volunteer monitors.
>
> Missions not counting as done is common, I’ve had it many times in Reach. I also still don’t have Steam credit for beating Halo 3 LASO. I just… it’s so depressing and frustrating that there’s so little communication between them and us. Makes us feel like they simply don’t care and we’re posting this stuff for a laugh or something.
I bet it is LASO isn’t something people do for fun.
Do they have a bug reporting system?
I just started playing through and got heroic progress for every mission up to oracle, during which i got no progress at all. My friend got legendary status for each of them and we have screenshots to prove it.
I have come across the exact same problem, just now in fact. Just beat Halo 2 on LEGENDARY, and it didn’t count for god sakes. My friend who hosted did get the achievement and each level accounted for. Meanwhile, I haven’t had a single mission count to my legendary play through. 343 this isn’t the first game altering bug I’ve experienced on The Master Chief Collection please get some of these fixed.
This has just happened to me and my friend as well on our playthrough of Halo 2 Heroic. I get they might’ve been busy with getting the rest of the Halos out but the fact that this forum is nearly 6 months old and it’s still a probably is kind of disappointing.
My Son keeps asking why he doesnt have achievements every time we beat a level. 
Hi everyone! Reading over the issues being experienced, it sounds like the host may be the only one getting progress for completed Halo 2 campaign missions / playlists. For those that are having this issue still affect them, please be sure to submit a ticket over on the support page so that we can be sure it flows down the correct channels.
Can still confirm that it’s still happening in late june. Just got it all done with my partner but only Great Journey counted for me. Host, twas partner, got everything. I don’t want to go through that brazen hell again JUST for my side to count, it’s bad enough for the skulls to be on the same difficulty for those to count. (least those WORK)