@Nezmo and @Ryan780, FWIW I have a couple regular GE zwave switches running fans w/out a problem for a few years now.
@dseg, I had a couple GE switches do this in the past. Both were controlling normal lights, and they were stuck on, and nothing would make them turn off. Luckily I had a backup zwave switch I was able to replace it with.
I think you have a switch that went bad. It’s not unheard of with the GE’s. If you’ve done everything to kill power to the device, including the breaker, and it still keeps the light on after bringing power back on - then you have a bad switch.