Ice Boxes don't slow spoilage

For whatever bizarre reason, Ice Boxes don't seem to work in Hamlet. It's something I noticed after a bit after I stored some ice in one. It was completely fresh, then I returned to find it melting. Along with that, the rest of my food was noticeably more spoiled then before.

I doubt it's a mod conflict, as Ice Boxes worked just fine on my other non-Hamlet files.