I’m sorry for repeating myself. But in principle you can pair Bluetooth devices with the Box 21. Here, for example, in addition to the remote control, I also paired headphones and a keyboard:
Connected are:
- Swisscom remote control RC2000
- Keyboard Logitech K375s
- Headphones ZX-1576 from Pearl **(No longer available)
**Maybe @RomanE has an idea why your devices can’t be paired with the Box 21.