I took it to the Samsung837 space, theres nothing wrong with it. And they love to fix things - I had a faint ghost of the nav bar at the bottom of my year old Note 8bat the time, they replaced the screen, digitizer, battery and all of the radios.Most everyone? I doubt it. You typically only hear the complaints, which is not an accurate representation of all the users. Sounds like you have a defective watch. I've never seen the error you posted. Don't doubt you, just never seen it. I think you're actually the person I've ever seen post about it.
I wear mine in the shower, running, eliptical, weightlifting, walking, HIIT. It gets plenty wet with sweat. The HR feature works just fine.
I'm guessing you've applied all the updates?
They knew exactly what I was talking about, had gotten others with the same issue, and said the new watches at the time were not likely to be any better.
If I'm just living, I can get a heartrate any time. If I'm sweating and moving, like on an elliptical or treadmill, it won't read, and tells me to dry the monitor or stop moving. Not so with a Fitbit. That's all.