Isolation Vault Tier 3 is the same location as Tier 1.

[denizakbaba]

After completing Tier 1 I went to the Abscess to start the tier 2 vault and after completing that I went to Albrechts Prospect to start the Tier 3 vault. This is where the issues start, it doesnt tell me to collect and of the vome/fass pieces nor do I have to start the mixer, the "door" is open from the start. I do however, have to get through the toxicity part of the vault even though the door to the inside of the vault is already open. after completing it i go inside the vault kill the single necramech spawns and then go to where the reactive crystal is to get the bonus room, sadly since this is the same vault as the tier 1 vault ive already completed the "bonus stage" and the reactive crystal and door is already open. Making it impossible to complete the bonus or get anymore loot. The tier 1 & 3 Bonus door as seen in the image below. 

[denizakbaba]

Oh also its not just once that this has happened its happened every time ive tried to do all three tiers of Isolation Vault. Which is only about 5 or so times