had this exact same problem. spent forever trying to figure out what it was because when i removed my custom content folder it would do this, but when i turned the setting to allow mods and custom content, it did work. turns out, curseforge downloads everything straight to the mods folder, when i was only looking through my separate cc folder within the mods folder. so i spent hours sifting through EVERY single mod, including everything from curseforge. it ended up being a mod called "Teen Jobs Collection" by AstroBluu. i did previously update everything on curse forge itself, but these files just seem to be completely beyond repair or updating. im not sure if it will be the same solution for you, but this is what worked for me. maybe try digging for mods that might've been misplaced or forgotten. either way i hope you can get it sorted out because i know how annoying this is.