Series 9 Apple Watch ECG no working on just me!

just bought the series 9 Apple Watch and the ecg works on everyone except me!

my partner and kids all get perfect readings then I try on me and the reading is all over the place and then says it can’t take it. What would cause this? Could it be a medical issue and Should I see a doctor?

if I hold the watch up on my upper arm I can sometimes get a better reading but it NEVER works on my wrist. I also always get poor blood oxygen levels on my wrist too! But works fine on everyone else