ECG upside down when the orientation settings are accurate.

Greetings Mattg800,

Welcome to Apple Support Communities. Great job on the troubleshooting you've done so far. We suggest unpairing the Appel Watch from the companion iPhone to help with this issue. Doing so creates a backup of the watch on the iPhone, so there's no concern of data loss. Follow the guidance provided in the Apple Support article: Unpair and erase your Apple Watch

How to unpair and erase your Apple Watch if you have your iPhone

1.Keep your Apple Watch and iPhone close together as you unpair them.

2.Open the Apple Watch app on your iPhone.

3.Go to the My Watch tab and tap All Watches.

4.Tap the info button  next to the watch that you want to unpair. 

5.Tap Unpair Apple Watch.

6.Tap Unpair [your Apple Watch name].

7.For GPS + Cellular models, choose whether to keep or remove your cellular plan. 

•If you want to pair your Apple Watch and iPhone again, keep your plan. 

•If you don't want to pair your Apple Watch and iPhone again, remove your plan. If you aren't going to pair with a different watch or iPhone, you might need to contact your carrier to cancel your cellular subscription. 

8.Type your Apple ID password to disable Activation Lock, then tap Unpair. 

After successfully pairing the Apple Watch back, let us know if this issue persists. We can go from there if needed.

We look forward to hearing back from you. 

You do not need a screen shot. Just look at a normal reading and imagine it upside down. I have this problem also. Reading taken last July is normal. Reading taken today is same but upside down. It has nothing to do with pairing as the readings being shown on the Apple watch when they are being taken are also upside down. Once I went into settings general orientation on the watch and made sure the wrist and crown were properly set, the problem went away. Apparently in July I wore the watch on my left wrist whereas today I put it on the right wrist.

Screen shot might help, or if using the crown for ecg prevents screen shots get someone to take a photo.

Are you any relation to Mattg800?

I do not know Mattg800.