I saw this again yesterday, where initially after the activity was synced only one move showed, then when I woke up this morning and checked sleep stats, I noticed the move had been duplicated.
This does not happen often for me, I have only seen 3 times in last month or so, usually I just delete one of the extras.
I have S9, latest firmware and beta Android app (4.12.6).
fbb44938-8c19-4e6a-b817-e2af048a8617-image.png