Can't upload my save to cloud storage because of too little storage space despite not having any other saves on it.

Hi, I was trying to load my current save onto the cloud storage so I'd be able to continue playing it from my PC but I keep getting the error message that there is not enough space left on it. I've deleted all the other saves that were uploaded onto it, as well as all but 3 locally saved saves without anything changing. I've moved saves between my PC and laptop multiple times before and never had this problem. I'm not sure it makes any difference but I've got the game through the XBOX game pass. I'd be really thankful if anyone knew a solution for this (there is probably quite a big chance I'm being an idiot here and don't see an obvious way to solve it).