I found the problem. I accidentally connected it to a logistics network at some point.

DaveMcW wrote:Is the inserter actually wired to the chest?

Yes, it is indeed wired up and not working

Koub wrote:Maybe should you set it to U-235 or U-338 on bith sides ?
A screenshot of yout setup or the save would help.

Oops, I accidentally put 238 in the brackets instead of 235. My bad!

I am trying to set an inserter to take out uranium 235 from a chest, but when I set it to [Uranium-235 > 40], it never does anything. But if I replace the > with a <, it will just try to empty the chest like there is no enable condition thing at all. Is this a bug, or am I doing something wrong?