Help Android Automatically Overwriting Folder Name

[Android Question]

I have a Samsung Galaxy Tab S2 and a MacBook, installed the new update yesterday. I always use Android File Transfer to move books onto my tablet but everytime I tried to access the "Books" folder it keeps saying "cannot access device storage, screen is locked" but my screen was not locked and MTP was enabled however I could still read the books on the device just not add anything new. I then downloaded the HandShaker app, after looking around I found my books in a folder under a different name "Kindle and then there are two Chinese characters" it won't let me copy the exact name. So I tried to rename it and it won't let me, then I deleted the "Kindle" folder and tried to put a new "Books" folder back on but it will automatically change the name back to "Kindle" and I can't change it. I can only access this file in HandShaker, AFT won't even let me open it but it says "Books" instead of "Kindle". I'm at my wits end and don't know how to fix this, please help me! I've tried so many different search terms in Google but I haven't found anything like this. Is there anyway to fix this without having to factory reset my tablet?

I also don't use the Kindle app, I use Moon, but I still had the Kindle app so I deleted it but that didn't help. I've also cleared my cache.