“After your dominant creatures Provoke, the others Provoke. Creatures that belong to the most common race in your party are dominant. This trait does not stack.”
The Hubbub Trait’s description says that when a dominant creature provokes, all dominant creatures will provoke. However, this trait only seems to work once per turn. So if your creatures continuously provoke the trait will only activate once, on the first turn of the first creature.
As far as the codex explains, there is no action limit on provoking and creatures that are already provoking should be able to provoke again, so I think it’s an issue with the trait. If this is intended, the trait description needs to be updated to be more explicit. This mechanic makes the trait much weaker than the description would imply.