If you are running the game through the microsoft store and your devices are on the same machine as Forza run CheckNetIsolation.exe LoopbackExempt -a -n=$id first. This ensures that Forza is allowed to send to localhost since it is a UWP app. In Forza hud settings enable set data out address to 127.0.0.1 and data out port to 7768 (or whatever you have set port to in the config).

Forza Horizon 4 support may not work as I don't have the game to test. I mostly included it as a precursor to supporting Horizon 5.

ids:

Motorsport 7: microsoft.apollobasegame_8wekyb3d8bbwe

Horizon 5: Microsoft.624F8B84B80_8wekyb3d8bbwe