I've had this same issue myself. I tried restoring my Enpass 5 database in Enpass 6 on Windows which was successful and I began syncing between my two Windows computers without issue; however my Android Enpass 6 never populated. This morning I checked on OneDrive and it appears that I have basically 3 Enpass wallets. My Enpass 5 wallet appears to be in /Enpass, my Windows desktop Enpass 6 wallet is in /Apps/Enpass Beta, and my Android Enpass 6 wallet is in /Apps/Enpass.
I think what I'm going to do for now is "manually sync" my Android Enpass 6 wallet by overwriting it with my Windows Enpass 6 wallet, which should at least bring some passwords into Android so I'm not dead in the water.