Horrific Visions vendors achievement bug

I unlocked the first vendor on my DK, then went on my DH and not only did the same run as on my DK but I later made a full clear with a mask on. On my DK I have unlocked the veteran vendor. But my DH doesn’t seem to be able to unlock that one despite doing a full masked run even. However, my DH has unlocked the champion vendor… which my DK can’t seem to unlock.

On my other characters, I can’t unlock either of the vendors at all.

Is there something I missed and I need to do? It looks like:

  1. The vendors are, as intended, unlocked only when you get the respective achievement.
  2. The achievement can only be “truly” gotten on one character, and then it prevents the others from getting it.
  3. That seems to mean that the vendors can, unintentionally, only be unlocked once, and on only one character, due to it’s being bound to a “true” achievement gain. The account shared achievement seems to block other characters from getting the vendor unlock.

The same is happening here, I have completed the veteran and champion achievements, but I am not able to buy the weapons with my alts