Mods problem

hello! I would start by saying that I used to have the sims 4 on my computer, I haven't played it in a while and I deleted it from the computer due to lack of storage space! but then I bought an external SSD and loaded the sims 4 on it again, no matter what I tried, I simply can't put mods in the game! No matter how much I put them in the folder, they're not in the game! I also want to add that when it wasn't on the external SSD, it worked, but nothing has happened since! and I've tried a lot of things! I suspect the external SSD is the reason it doesn't like it, but I don't know anymore and I'm starting to give up!