I have three zigbee routers that I’ve used over the years. A now very old Conbee Stick, an Electrolama zig-a-zig-ah! (zzh!) and a SONOFF Zigbee 3.0 USB Dongle Plus ZBDongle-P. I consider the Conbee to be dead. It’s not, it works just fine, but my network has far outgrown its capabilities and it exhibits very odd behaviours if I try to connect eberything to it.

SONOFF Zigbee 3.0 USB Dongle Plus ZBDongle-P

Ensure your current user is in the tty and dialout groups.

If not, you should run:

usermod -aG tty ${USER}
usermod -aG dialout ${USER}