ZymKey not working on latest Buster (8Apr20)

There are general discussions of GPIO pin conflicts in the documentation but your suggestion is good to include checking the 1-wire interface in the troubleshooting section.

We’ll fix the access problem with that link too.

You can use an alternative GPIO pin for the Zymkey. The steps are outline here:

The other way would be to remap your 1-Wire interface (may be easier with your wiring?) To change the default GPIO pin used for 1-wire communication edit /boot/config.txt and add gpiopin=x to the end of this line (x is your new GPIO pin, no spaces), then reboot: