Garmin support site saying that is available in the UK. I cannot find the damn ECG thing under my fenix 7 pro's details page. No "finish setup" or anyhting appears. Firmware version is 20.22 Garmin Connect version 5.12.1 (android) I am in the UK. My watch is brand new, it was replaced by curries few days ago for bluetooth audio crackling issues. My new device does the same cracklng after update to 20.22. I think right now these garmin watches are not worth their money at all. They should be a £200 watch not a £579. I did a full reset on my watch yesterday just for this. Very disappointed. Should have just got a used fenix 6 pro solar instead.
On the ECG support, I'd make direct contact with Garmin support in the UK then. My experience has been good, though it could take a couple of days before first response.
This is primarily a user forum so your complaints are only going to other users, which will not solve things for you in the mid term.
I assume your mention of £200 is related to a used 6 model, otherwise seems a bit random.
