I still don't understand how this is technically possible in the first place, I mean isn't the Windows version the same as the one that you download from the MS Store? Apparently not, and I have never been a fan of app stores anyway.
In my experience, most Microsoft Store apps are different to the standard Windows applications. One quick example is VLC Media Player. The problem in this particular case was that Enpass was failing Store validation. This post on the Enpass forum sums up the frustration. As I linked to in a previous post, the problem was escalated to Microsoft as a Microsoft Store error.