Sad that a $650 watch can't accurately record sleep time. My Ultra adds any time I sit down to sleep time. The metrix are not accurate since it thinks I'm sleeping all the time.
It records sleep when you are relaxed enough that your heart rate and respiration go low enough to be mistaken for a sleep state. Try making sure you have some movement while seated. I usually check my health app before bed if I've been relaxing for a while and delete any erroneous sleep tracking. Since the sleep statistics are for my edification only, I don't worry too much about my sleep stats being "off". I know when I went to sleep.
