Heyo,
I completed Long Night of Solace on Legendary Co-op yesterday, along with all of the other missions in the Reach campaign.
For some reason, LNoS hasn’t registered my Legendary Co-op completion, where the rest of the missions have. It also registered as Legendary completion for my Co-op buddies.
I completed it today on Solo Legendary, and the missions remains uncompleted for Solo runs.
I had IWHBYD and Grunt Birthday Party on, but I don’t know why that should make a difference.
It’s pretty frustrating as it means I can’t get Legendary completion achievements.
Cheers for any help!