My Garmin tells me I get about 1.5 to 2 hours of REM sleep nightly, but I seldom if ever get any deep sleep. 2 minutes total in the last week is all. Is the Garmin very accurate for sleep monitoring?
Nope, Garmin is the worst of all major smartwatch brands for sleep tracking. The slightly better Firstbeat algorithms were also not applied to this watch. It's good to track runs but nothing else.