Wrist OHR query/issue

I have my Wrist OHR set to Status=Auto in the settings and also have Pulse Oximeter  set to Sleep Pulse Ox = On and Acclimation = All Day however the Wrist OHR seems to have a mind of its own and is often not on and I am not seeing any HR reading on the watch face. Sometimes it shows, often it doesn't. I'm assuming it is a software issue but from a quick search I can't find anyone else reporting the same issue.

Any ideas?

TheSalamander