As the other poster suggested, AutoSleep is amazing. I've found if my watch is too loose it won't record sleep well. It's also a known problem that Apple watc

As the other poster suggested, AutoSleep is amazing. I've found if my watch is too loose it won't record sleep well. It's also a known problem that Apple watches "backup" bugs (which I've experienced twice now). If the problem still continues, I'd recommend you fully unpair/reset your watch and setup it up as a new watch (do not restore from backup).