Voeld vault change?

It is a bug.  The very first time I did Voeld, I had a manageable depleting Life Support bar right up until I reset the vault.  After I reset the vault, a few Level 2 areas remained, but the Life Support Bar disappeared on the flat areas like around Hjara and Techiix.  I lost that playthrough shortly after during a lightning storm (corrupted the file).  When I got there a second time, I had an extremely fast depletion of the Life Support Bar right up until I did a fight on the flat at the bottom and used a heat lamp in that area to recharge the life support bar mid-fight.  The Life Support Bar then completely disappeared and stayed gone right up until I reset the vault.  I walked from Hjara to Techiix just to prove the point.  After resetting the vault, it came back in the "accelerated" state.  It made the architect fight nigh impossible for me, so I started Voeld again and the Life Support Bar disappeared again at the same point; however, when it came back after resetting the vault, it wasn't near as fast at depleting, so I was able to get through the architect fight.

Now, on my NG+ run, I died 3 times just running from the ship to the first heat lamp on the way to the resistance base (depletion of the life support bar was absolutely intolerable).  So, I backtracked the file a bit, re-did some stuff on the Nexus and then came back to Voeld.  This time, I finally got a "normal" life support bar.  I'm still on Voeld right now and haven't reset the Vault yet, so I have no idea what I'll wind up with at that point.

I don't know what triggers it, but I think if you wind up with a situation where you can progress, the workaround seems to involve backtracking a few quests.  I tried many times just to exit and reload the game, and the bar came back (or stayed completely gone) just as it had been before I exited the game.  When it's gone it's nice, when it comes back too fast, it's murder.

yeah it's as @upupawayredux says Voeld life support things are a bit bugged in that you never know what your going to face and how quick it's going to drain especially as it drains when down in the vault as well. The only workaround I can suggest is use the fast travel points once you've set them up and stick to the Nomad and only come out once you've reached your objectives on the planet. When it cvomes to the vault the only way to get through that one is use the shields to recharge yourself. It can be a bit annoying when your trying to figure out which consoles you need to hit but there's unfortunately no way around it.

Voeld is bugged to buggery. I even managed to place the outpost before I activated the Vault on my first playthrough. If you lift off the game updates the codex entry as if you'd activated the Vault.

The codex entry change must be triggered by the setting of the outpost only.  In my current playthrough, I just reset the vault and I've lifted off to return the moshae to Aya without setting down the outpost... my codex entry has not been updated with the vault information at all.

I thought that it was a F e a t u r e, really. To add some difficulty.