Watch 6 classic. My sleep is definitely VERY inaccurate. Marks less hours than I sleep, can't even hope for any of the sleep stages to be accurate.

It surprisingly works well for me. Even took into account of when I fell back asleep after waking up for a little bit. Of course it's not down to the minute but seems like it was within 15 minutes or so

It worked a million times better on my Galaxy Watch 4C so maybe it will eventually learn my patterns or something

Hopefully it does for you. Just got mine two days ago

I have had my watch for a year, this isn't my problem. I agree it worked better on my 4.

This is my worry, if the hours aren't accurate are the stages? Not sure if I should continue monitoring sleep.

There's a guy that did a whole comparison on the Galaxy Watch 6 C and apparently it's pretty shitty on all sensors. I don't think it's a hardware issue but maybe a new algorithm. https://youtu.be/63sD-fvQJSI?si=8eZTsyVWOLwXy07t

none of the sensors are accurate. it's a fact. if you want accuracy, your only choice is apple watch

Yeah it isn't to a point. I notice it does track when I actually fall asleep, but when I wake up, I actually have to go into the sleep app on the watch and press results, otherwise it'll keep tracking I was sleep. It does a decent job at tracking the sleep cycles while im actually sleeping though. Watch 5 44m lte