Fan shim light not working

I installed the software for the fan shim today and a green light appeared on the fan. I have now updated my firmware to take advantage of the USB boot capability and now the green light isn’t there any more.

I have checked the list of running services and the fanshim service says it’s enabled, but I still don’t see a green light. Running the script brings up the green light, but then I have to keep the terminal open otherwise it stops the script and the light goes away.

Also if I run the examples/ file it says the service is active, but if I then run systemctl status pimoroni-fanshim.service it says the service failed to start.

Have I broken something and if so, how can I fix it so it works again?