Working as intended, or something went awry?
In my history of playing the game, I’ve always experienced the A / B vaults, like everyone else.
Myself and many other people have gotten NO vaults back to back recently, while everyone else has gotten TWO VAULTS back to back.
Sup? lol
Not everyone else. I, and I’m sure many others, got a vault last time and regular token this time.
…okay?
He is simply pointing out that the assumption:
is incorrect. I also only got a vault for the current PVE.
I think we both know that the chances of getting a response from someone who actually knows how it is supposed to work is slim to non-existent. 
Regards,
Cypr3ss.