CIFS difficulties

[Morpheus]

First, let me explain what I am trying to do:

I get several files that, once downloaded, I like to temporarily store on a USB drive attached directly to my ASUS AC1900P router. I also own an ASUSTOR AS5304T that I use to store files and backups that I want to keep on a more permanent basis. So, in order to make the temporary files more accessible throughout my network and to third party ASUSTOR software, I tried creating a CIFS folder. After several unsuccessful attempts to get the server to recognize the specified remote folder (Ref 5015), I decided to try allowing guest logins in my router and seeing if the "guest" login type would work. And it did.

However, I don't feel very comfortable allowing guest logins on my router. So, I was hoping someone here might have an idea as to why the "guest" login type works and the "normal" type keeps giving me an error that it can not find the specified remote folder (Ref 5015)? And even, perhaps, a way to get the "normal" login type to work so that I don't have allow guest logins in my router anymore to get CIFS folders to work on my ASUSTOR?

TIA!