I installed the new Enpass (with the trapezoid icon) from the Windows 10 Store and attempted to set it up just like the old Enpass from the Store (Round Icon).
When I connect to my desktop with Remote Desktop Connection (RDP), all I get are black windows where I should be seeing an interface. When I right-click on the enpass taskbar icon, it too renders in all black. I ran the older Enpass at the same time for comparison of what I'm expecting and what I'm getting. See screenshot.
I've seen this happen before in other apps, and they always required some kind of application update so they rendered properly in a RDP session. Currently, this is the only App that runs like this, including all other apps from the store (and games, yeah, games from the Store work in RDP - more or less).