I have a Venu 2s.
In the beginning the watch was great. Less than a year later it has completely given up on reading a pulse, ox%, breaths, etc. I have followed almost every forum possible including factory resets, changing certain settings, looking for beta updates, and more. Everything in the watch should be telling it to record. The heart icon is red with the --. There is absolutely no green lights flashing like it used to. You can go into each of the pulse, ox, breaths, etc. to try and force them to use the sensor, but it'll count down from 30 and say it's an incorrect fit. I have watched each test and not a single one of them will make the green sensor lights come on.
CURIOUSLY, I was looking through every setting possible and I noticed the watch has listed the sensor version as 0.00. I also noticed its software is at 11.14 though i thought I saw 11.16 is out. I'm linked to my phone as per usual and it claims I am up to date. I'm not sure what to do at this rate.