Use cover.jpg file as cover instead of guessing it for mobi books

Ubooquity often shows the wrong cover for mobi format books (about half the time). It usually picks up a cover from another book by the same author, or some random image from within the book. From what I understand, it's trying to 'guess' the cover for mobi format books. 

Does it have to do that? If the option 'Shared books are in a Calibre library' is ticked in settings, then Ubooquity should simply pick the 'cover.jpg' file in the same folder as the book, and use that as the cover. Ubooquity doesn't need to guess the cover at all. Is such a fix possible?

I'm using Ubooquity 2.1.2 installed on a QNAP NAS. I've noticed other threads mentioning this. I responded to an old thread with the same issue, but was not sure if it got review. Apologies for the duplicate. Any input would be appreciated. Thank you.