Thx @Garima Singh
I’ve been using Enpass for about 6 months and have had this problem again and again from the beginning on all my devices. Those are
MacOS latest with Enpass latest
iOS latest with Enpass latest
Linux Mint latest LTS with Enpass latest
and also on my mum’s old iPhone with iOS 12
Im using 3 vaults and have the problem in all of them. The sync services are
iCloud Drive
Google Drive
Webdav with NextCloud
Other answers
I'm not getting any error messages, sadly. It just silently fails.
Yes, time and date is on automatic on all my devices
The last synced time seems to be shown correctly on all devices at all times
My gut feeling sais, that it's the sync services, that want to have the password reentered on a regular basis. Other apps/os deal with this by sending me notifications. For example my Exchange and my Google account on my mac require the password reentered every few weeks/months. So MacOS sends me an notification, that they need my password. I reenter, problem solved.
With Enpass it might be the same. Only that Enpass doen't let me know when sync fails (which is probably because the service wants my password again) and I have to go looking for the problem until I finally stumle on the vault settings and see the red notice there.
See, most of the time Enpass works perfektly, so no quickfix needed.
But please, Enpass, send me a notice when sync fails. Thanks