Duplicate Ebook vs. Logos

For a few of the resources in my library, I have two separate books that are exactly the same - not a revised edition, not multiple volumes - side by side exactly the same at every point.  The only difference I find is listed under "edition" : one is "Ebook" and the other is "Logos".  Sometimes the "ebook edition" will have a copy of the cover in the file, while the "Logos edition" will begin on the title page.

What causes this?

Given that they are both from Logos and in the Logos software, is there any actual difference in the books (tagging, indexing, etc)?

I discovered this when I was reading a book on both my computer and tablet and was frustrated that the book never seemed to be in the same location when I switched devices. Turns out I was reading a different duplicate on each device - which also affecting my highlighting.  I'm trying to determine which version to "hide", or if that is even the best option.

Thanks community!