So biohackers like Brian Johnsson and other have recommended falling asleep to theta waves like this: https://m.youtube.com/watch?v=KcU6w1Pr5gc&feature=youtu.be

Its said to almost double deep sleep. I've tried it now and measured with my steel HR sport, but it's acting very weird. For example last night I fell asleep with theta waves at 2:15am ish, and my withings app says I fell asleep at 00:45. This has happened two nights now with theta waves music. I absolutely didn't do anything to confuse it that I was sleeping, I was clear awake and talking on phone etc before sleep.

Im guessing that it's just assuming because of some deep sleep theta pattern that if I'm in this deep sleep already I must have fallen asleep at this time(maybe it tries to error correct itself?).

Anyone else noticed this? Any idea what's going on?