casivaro I believe we are mailing through support, or is that some one else? Because it sounds the exact same.
Was the Onyx+ at some point paired with another device than your headset?
Can you turn off your headset and let the device connect to your phone (not the haptics app, just the phone's BT).
If it establishes a connection, can you unpair it and disconnect?
Then do the same with your headset, and 'Forget all BT devices'.
Turn off everything, toy, headset, try to avoid other BT transceivers (BT devices that can both send and receive.) - Start the headset again, pair the Onyx+ before opening any apps!
If pairing is done, then launch the HC app.
If you don't get Hello strokes, then it's (still) not working.
But let us know!