Dominos works with the blizzard keybindings.
Make sure you don't have the extra action bars enabled in the Blizzard options menu.
What happens if you just enable Dominos + Dominos_Config?
Its on my list.
I don't have a good way to turn it off when in a vehicle at the moment.
Dominos_ActionSets is meant for this use case
/dominos -> Check Use Blizzard Override Action Bar
That's more or less a Blizzard thing.
That is probably due to another mod you're using.