WX-78 Illumination circuit not turning on, in lights out.

In my original lights out world, I went into the caves with the optoelectric circuit, learnt the illumination circuit, then I left the caves. On the surface, I made the illumination circuit, took out the optoelectric and speed booster v2 circuit and put in the illumination circuit and thermal circuit in that order. It turned on after the 3 module things were fully charged. I went into the caves again an then left straight after seeing where it led. When I left, it turned off. 

I made a different world and gave myself an illumination circuit using the same world settings (but small overworld and caves) and it turned on. But when I entered the caves it turned off. I left the caves to see if it turned on back in the overworld but it still didn't turn on. It only got fixed when I took out the circuit and put it back on again. It didn't seem to matter if I had other circuits on because my original run had the thermal circuit on and the world I made for testing only had the illumination circuit.

I don't know if this is relevant but I did a ruins rush before finding the lunar grotto on my way back to make the circuit.

I'm also not playing with any mods that change WX-78's mechanics.