I got the Watch3 since almost a year, the device is giving wrong readings about deep sleep, it is always low and sometimes 0% regardless what i do, i have made some researches and it ended up seeing a lot of discussions with no solid answer from Samsung, so here is what i did to put an end to this.
i have done all the hardware and software troubleshooting, including resets, cleaning the sensors and adjusting the tightness of the strap, and even used different types of straps.
one night i fixed the rotating bezel with a tape tp make sure this doesn't affect the reading, since it will definitely give a wrong indication about being awake.
so here is the moment of truth; i slept with Watch 3 on one wrist and a Huawei watch fit 3 on the other, the results are dramatically different, the algorithm of Huawei seems to be more accurate while that universal secret of Samsung algorithm stays a big question mark.
how did i know?
i repeated the same experiment over a week with different watches and sleep trackers, compared to Samsung, and compared to other brands.
unfortunately, Samsung is a big fail when it comes to this, guys you need to update this algorithm, look scientifically into how it works, and give us a one time solution ASAP, we do expect accuracy from a watch that is 3 times more expensive. and way into this field before the new players.