I am using an Android 10 Phone and Garmin Connect Mobile (4.29) uses a lot battery (~25% of all usage). A lot more than any other application or the screen. I have gave all needed rights to have notifications on the watch and also excluded GCM from battery optimization as it was retaining the notifications.
As far as I remember there was no huge drain with same settings with previous releases of GCM.
Does anyone experience the same?