With the latest firmware and/or Connect App my wallet got deleted and I was unable to enable it again (could create it in the app but it was not transferred to the watch). After trying almost everything (factory reset, re-install app, etc) for a couple of hours I tried to do it with an iPhone (I own an Android device Oreo 8.0 OnePlus 5) I succeeded.
Obviously something is wrong with the Android version of the app since 2.9. Hopefully this will be fixed soon since I am not a fan of iPhone or Apple and will definitely not buy an iPhone only to be able to pay with my watch.
Apart from that: once the card is on the watch it is super easy to use the watch on contactless terminals. Never had problems - works exactly like the NFC plastic. Great job.
Regards,
S.