I bought a Watch 3 about three weeks ago, and I have exactly the same problem... a circular rash underneath where the main body of the watch sits. I for not wear it tightly.   I am suspecting that it is something to do with the sensors on the rear of the case. HOWEVER... I previously had a Fitbit with similar sensors, which I could wear for weeks at a time, and NEVER had any rash problems with it. But within 3 weeks of this new Watch 3 I have this bad rash. Very annoying and disappointing.   Why...? ... View more