heart rate apple watch series 4- inaccurate HR rates

I found that with the latest update (?) my Apple Watch has been giving some wild values, ranging from 30 bpm to 200 bpm while at rest or lightly moving. I wore a finger monitor to compare and sure enough, while walking around my Apple Watch showed a clear 47, while my finger monitor showed 89. That's a big difference. Also, running up and down the stairs, the Apple Watch showed an HR of 40bpm above what the actual reading was.

Yes, I've read all about watch position, straps, calibrating etc. None of that helped.

Has anyone else had these wild readings?