[freerangebat]

I have only about 20-40 mins of deep sleep out of 7.5hrs according to my Apple Watch S5. Recently I found out I can easily double my deep sleep by having a one hour nap in the afternoon. It messes up my night bed time though.

[Melatonic]

Might just be that your watch is inaccurate - I would say try a different sleep app to start. I found they varied somewhat (this is on Android).

I think I actually got the best accuracy by placing a fitness tracking band around my ankle (I used a mi band) with the phone next to my head.