This is probably a really silly issue with a totally easy solution I'm not seeing, but when I add the files for Tech Reborn and Reborn Core to my mods folder in .minecraft, they don't seem to load when my installed Fabric profile boots up.
I have other mods in the mods folder and they all load just fine.

What stupidly obvious thing am I doing wrong?

Randomly started working without explanation. I wish I could delete this issue from your issue tracker. sry