Campaign progress not being saved

I got the issue that my campaign progress of the mission Shutdown in Halo 4 mcc on Steam is not being saved, i finished the mission now for the third time solo on legendary with no results…super frustrating. All missions before that saved properly.

I already know this bug from Halo Reach mcc on steam which i have from the launch until now. There its a bit different, its kinda 50% random if the progress is saved or not.
My friend also got the exact same problem.
I posted my issues multiple times on steam with some smaller reactions of others players, some got the bug too; others not. To this day Reach isnt fixed or playable for me and i expect that for Halo 4 also nothing will be done in this case.
As i am someone who puts a ton of time into videogames and attempting to 100% achievement the MCC on Steam thats super fun killing and no point in playing anymore. I still didnt get a single reaction of the developers of this bug being adressed or noticed; pretty disappointing.

Is someone here experiencing the same problem? Or a similar one like that? Can someone eventually help me getting rid of it or texting the developers?
Best regards, Razor!