Another thing to try is to clear all priorities via the app or hyperion-remote, because maybe another process (Kodi for instance) is claiming access with a higher priority
Will double check the priority code in case it's hard coded but believe that was migrated from AtmoLight correctly.
Found out why I don't get any notification, I was facing THIS issue with Windows
Now I get the error D3DERR_INVALIDCALL (-2005530516)
Also disabled everything except the JSON/protobuffer
Any other clue?