Fibaro motion sensor (FGMS-001) issue - green LED always on

I recently connected a FGMS-001 from Fibaro to my home automation setup (using Vera Plus). The aim was to have it automatically lower to window blinds when the lux falls below a certain level, and automatically raise them when motion was detected in the morning. Using Altui & Thingspeak I also logged the lux & temperature values.

The sensor worked fine for 2 weeks, however 1 night I noticed the lux levels were at 1700 instead of 0. I went to check and noticed that the sensor was fully green continuously. I’ve since done a factory reset, excluded it from the network & re-added it several times, so far with no luck.

Currently it’s not included to my z-wave network and still glowing green: according to the manual this means the sensor communicates directly with the main controller, however it should only do that in z-wave range tester mode - which it is not in as far as I can tell.

Has anyone had this issue & found a solution? Is it Vera related? Did the altui / thingspeak integration somehow cause something to go corrupt? I’ll probably ask on the Fibaro support forums as well but wanted to check here first.