On latest 9.1.3 build for mix 2s there seems to be some kind of account or sync problem. I have a calendar widget on homescreen which displays my appointments, which are synced via Google. The appointments show up after I've opened the calendar app (in this case Google calendar or mi calendar) and ticked the specific account again. But after a few minutes they are disappearing again from widget and app as well. I've tried several widgets, all with the same result.