i think you cannot use the ECG function even tough you bought the unit from the country that supports ECG. it is because of the apps will trigger your current location to make sure you are in supported region... if you're outside the region, then the ECG function won't work...

Just checked with Apple support.
ECG only available in certain region and it follows the location.
Apple Support told me that we can use it in allowable region only.
Which means that in Hong Kong, we can set it up and use it normally but not in Malaysia and elsewhere that Health app not supported.

My case-- I've a AW4 bought in Hong Kong having Malaysian AppleID, facing the same issue.

I think the ECG activation is based on the:
1. Point of sale
2. Location
I tried to spoof the location (eg HK), then reinstalled watch OS. Didn’t work 🤣😆
I hope the next OS release would include the ECG for Malaysia.

So US watches which was able the previously use ECG in malaysia will not be able to use now?

The ECG is still working on my OS5.2 watch.

I try to set up in and change the region to singapore, still not working, it look like still need to detect the location, not sure if next time when I am in singapore, can I get set it up since the location will be in location

If I buy in Malaysia. Then I go SG. Can it still in active when I back to Malaysia?

do i need to use local sim card?

let say i go to singapore and want to activate it, do i need to buy singapore sim card?

So is that means with my Malaysia Apple ID on my iPhone, I need to be in Singapore and get local SIM card. Then I will be able to activate after getting Apple Watch Singapore set? Or I just use someone Singapore Apple ID too?

Thanks. Which model you purchased? With cellular?