Not sure, wish we knew =P. I am running a custom ROM, but I don't see how that would affect downloading Enpass. Especially since it worked before you updated your app to 6.0. If I search the Play Store on my phone, I don't see your company, or Enpass. If I use a direct link to your app from your website, I get this error on my phone: (see attached image).
I'm on Android 7.1.2, phone is a One Plus One. App is not updating, and shows as "Not available for my device" in the app store if I use a direct link.
Still can't update to Enpass 6 on my phone.