I can confirm this. Enpass and the opera plugin were working just fine yesterday until both an update for opera and enpass (desktop, mac) were rolled out today. It is really an issue with the Opera plugin, the extension for safari is working well with the enpass update (5.6.10).
Version:
53.0.2907.68 - Opera is up to date
Update stream:
Stable
System:
Mac OS X 10.13.4 64-bit