I had the same problem and it turned out that I had forgot to add my user to the crucial groups (I use core).
sudo usermod -a -G dialout,gpio,i2c homeassistant
Fixed the issue. For a diagnostic I must add that in the console I was getting the following errors/warning
2022-02-08 17:00:58 ERROR (MainThread) [zigpy_zigate.common] Unable to set PiZiGate GPIO, please check configuration
2022-02-08 17:00:58 ERROR (MainThread) [zigpy_zigate.common] No access to /dev/mem. Try running as root!