Do you have selected the calendars to be synchronized in your DAVdroid account?
Wrong time on calendar events
For me that looks like the calendars are set to different time zones (e.g. in the settings).
Can you post the details of the events in both calendars? Or maybe when you edit the event in the calendars, do both say Moscow time?
You can also have a look into the calendar settings of both apps to see which time zone they’re using.
The phone is updated automatically. In confluence, the calendar is set to “Moscow” +3
When the time of the event is changed on the phone, it also changes into confluence in the other direction.
I have the same problem, but live in germany. It’s about regularly repeating events. I record the appointment on a server (posteo), it repeats e.g. every monday at 08:00 a.m. Until 25.10.2020 it was shown correct on my android device. But since changeover to wintertime (MEZ/CET), it is shown on my android as an appointment at 07:00 a.m.