It looks like the new Google's Pixel 4 watch comes with yet another incompatible change in charging technology. This is a ridiculous situation. The original Pixel Watch used one type of wireless charging. Then the Pixel Watch 2 & 3 removed wireless charging and swapped to a different charging mechanism. And now the 4 has changed again. So three different charging cables in under three years.…
I didn’t try actually contacting customer service about it but from talking to other people it has to do with how the watch moves around during exercise that gives the false readings. If I just sit still and compare to a pulse oximeter it stays pretty close but if I am biking or walking around the values change drastically. Then for some reason while when I sit down or lay in bed my heart rate is around 65 it says my resting heart rate is in the 50s
It seems like a reading issues rather than a hardware issue. Try placing the sensor on the inside if your wrist where the skin is softer and veins are more prevalent. Also play with the tightness and fitment location up or down a little. Go to settings turn data to gather every second. Update the hardware and apps during syncing with phone or wifi. I know mine can be off under vigorous fan biking where your really thrashing your arms. But it’s fairly accurate any other time. I’d like to note the resting heart rate also appears to be an average of sleeping and awake values as an average. I’ve noticed mine doing that same thing. My resting us regularly in the mid 50s with slight variations.
If you do intensive exercises or more moving than otherwise a watch on your wrist could reasonably keep up with. I highly recommend pairing a Polar H10 (roughly 100 usd) strap to your garmin and that’s hospital/lab grade accurate. Pairs right to the watch and nothing else is needed, syncs the data accurately and to connect app as usual. 400 hour battery life, adjustable, comfortable. Check it out. Good luck.