Unavailable entities after adding through config_flow

Development
1

I have created a new integration for Universal Powerline Bus (UPB) devices. I’m using config_flow. I’m getting a situation where the entities are showing as Unavailable when I believe that they should be available. Here is how I reproduce…

  1. Configure the new integration, through the config_flow process.
  2. A number of light and scene entities get created. All are Available.
  3. Remove the integration (through the GUI)
  4. Recreate the integration, through the config_flow process.
  5. All of the entities are Unavailable. When an entity has a state update the entity becomes available again.

Since scene entities don’t get state updates they remain unavailable until I restart hass on my laptop.

Why would they be showing as Unavailable? Is there something on (re)creation that should be done?

Code here: https://github.com/gwww/core/tree/upb/homeassistant/components/upb