Hi there.
So I have Galaxy S10 and Watch Active 2 and no functions related to Samsung Pay don't appear either on the watch or in the Wear app. I can install an app on my phone but not on the watch.
I would hazard a guess that it is related to the country of origin. The thing is that I'm Ukrainian and have an appropriate account in Samsung, Google and so on. No Ukrainian banks support Samsung Pay, so this feature must have been suppressed from the device. It is impossible to connect any Ukrainian card.
But now, due to the war, I was made to move to the EU and I have opened a local bank account and have its card. Therefore I should be able to use Samsung Pay on my watch.
All the basic stuff like resetting and re-installing apps I've done, so the problem must be more sophisticated.