I think its some kind of game exploit on other players , because again - vault and all gates was open, and boss even alive, but what is wtf - how they or what happens to last gate,because u cant press pressure plate while boss is alive there…
either that either vaults do not refresh, but mobs still spawning…
I play on a private server with 3 people on it at moment and we do vaults as a group but finding loot boxes empty or just not there , doors open at boss room and have found a couple of bosses gone after hours and hours of not being in the vault but it is not resetting. There is a big issue some where with their respawn rates in these vaults. The vaults are locking as they should and unlocking but Its very frustrating to do the full vault and get a bowl of tar out of one chest for your time.
I know its early access but this makes no sense that the vaults do not reset correctly.
Just had the same and happens a lot of times run through all gates locked kill boss open gate main chest empty, official server. Seems the chest are taken longer to respawn than the actual vault which seems a bit stupid. I have even waited at the gate for it to turn blue (available) ran the whole vault kill boss and main chest empty.