Backlog Chromatic Orrery and Kurkesh, Onakke Ancient have a bugged interaction

Orrery should allow Kurkesh's triggered cost to be paid with any colour of mana, but MTGO currently requires red even with Orrery in play.
Upvote 1
It seems to be a bug with costs that can be paid during a triggered ability. The same thing happened to me when I tried to cast a card under Widespread Thievery. Even if I tapped my lands for the actual color it wouldn't take, but never does the interface allow me to spend mana as though it was any color for the ability.
See event#262765753, Game #854350308 for an example.