Can't remove partial stacks from cross-realm guild banks when not on the guild's realm

[Insert standard “me too” comment here]

The workaround is:

  1. Take the partial stack out of the guild bank
  2. Add the two stacks together in your inventory
  3. Move the stack back to the guild bank.

Really annoying.

Another workaround:

  1. Move all the reagents to the Warbank
  2. Log in to a toon that’s on the same realm as the guild
  3. Take out all the warbank reagents
  4. Add them to the guild bank normally