I have had this bug quite a few times and it's absolutely infuriating. Heres what happens: You do a mission (in My case it usually happens during Omni Fissure Void Cascade) and when you exit the reward/completion screen is blank, and sure enough all your reward are missing. All Steel Essence, resources, arcane, Prime parts etc.
If you close the game and open it again, there's a chance you get a message from Ordis explaining, that some Things have been retrieved. But its usually just Prime parts. Meaning Im missing something like 30 Steel Essence, 10 arcanes of different types, 10 Riven Slivers, all 8 voidplume + void opinion from Void Angel and all other resources, xp etc.
Another note: It seems to me, that when u get the message from Ordis, that he has retrived Prime parts, that this is also bugged. Im 99% sure it will give you the reward that came from your own relic! Meaning that if a squad mate got lucky and got a gold part, and you picked that because you only got bronze - the game wont remember your choice. It will remember what was in your Void Relic and give you that part - NOT the gold part you chose.
And let me stress something - this happens Even when all squad mates exit at the same time, so its not a matter of host migration. I would never NOT exit when I see a squad mate exiting, because of the awful host migration issues.
So TLDR: this is absolutely breaking the game for me. Resources is a HUGE part of Warframe, and when I do a mission it feels like a gamble every time. "Will I have wasted 30-60min of My time?" Some times I dont want to gamble and simply play a different game.
Is it possible to report this anywhere and get everything you lost???