I was testing this fix and something very strange/scary just happened: I upgraded, reopened Enpass (it asked me for the password) and made sure everything looked OK. I then put the the laptop to sleep and woke it up after an hour or so. When I logged back in, I was able to reopen Enpass, but my vault appeared completely empty. NOTHING WAS THERE!
Restarting the app fixed the issue, my entries show up again. But of course, that defeats the fix, as I had to enter the master password after restarting the app.