Forgot to say:
I installed the Flic App on the TvBox.
Beside the fact that it runs sideway (like if the TV set was a phone) when I try to add aFlic button, it ask for location permission (correctely):
"You location services are turned off.Android requires location services to be turned on to scan for Bluetooth devices."
"Please tunr on Location services and try again"
When you press to confirm it opens the OS setting for Location (correct) where, being a TvBox, there is only the choice "Use Wi-Fi to estimate location" or "off".
Chosing the first, does not solves the problem. The OS reports still that "no apps have requested location recently"
This seems to be a quite known bug in Homekit. If you see the Flic wobble inside the Home app, then we have successfully delivered the event to Homekit and there is not anything more we can do at that point. If the action at this point fails to execute inside Homekit, I suggest you to go to Apple's support and tell them about this issue.
Unfortunately BlueZ which is otherwise the commonly used Bluetooth stack on Linux didn't provide the stability, features and responsiveness that we would like for Flic. That's why we made our own direct implementation. It will use one HCI device, so if you want to use Bluetooth for something else you can add an extra dongle. If you want to share one Bluetooth controller you can always implement the Flic 2 protocol yourself for your chosen Bluetooth stack, according to our protocol at https://github.com/50ButtonsEach/flic2-documentation/wiki/Flic-2-Protocol-Specification.