I am trying to have a texture pack that will show whether a hopper is enabled or not. I have created both a new blockstate file and model (attached). When I put a Redstone block next to the hopper, the visual appearance does not change. When I open the hopper's UI and place something into it, then the appearance does change to add the new visual. Removing the Redstone block leaves the visual in the new state, until I (again) put something into the hopper.

I would expect that the visual state of the hopper would be updated whenever the block state changes.