I have Wandering Spirits set to be cast on Right Mouse Button.
I opened a shop and started sellling items using “shift-RMB”, and the skill was being cast as if I wasn’t in the shopping screen.
This never happened with any other skill, and it shouldn’t with Spirits.
Update: Happened with Aura of Decay as well.
This leads me to a hypothesis that actualy all skill commands are carried out while shopping, but ones that require a target understand that cursor is in inventory, and do nothing. But those skills that don’t have a target do trigger.
Not sure f it’s a bug, but I find it very annoying while shopping.
Also I find it extremely unlikely that shopping in combat will be required at any part of the game.