When it rains, the solar panels put themselves away, like when it is night, but the cart continues to run like normal. It appears to also continue to run at night, when it is raining. I don't remember it doing this before the rain started.

This is all tested on my survival world, no cheats, so I wasn't able to isolate the exact cause. If you need more details about my environment, let me know, and I will share.

SC2 2.1.0.59
Forge 12.18.3.2185