Apple Pay on Watch S8 Failure to Open
Apple Pay on my watch works in the first shop I go into (dbl press side button on Watch) and then for successive shops, it does not work. What I mean by not working is: Dbl pressing the side button causes the watch face to be replaced momentarily by app view (list view in my case) and then it bounces back to the watch face. Repeated attempts to get into Apple Pay mode by dbl pressing the side button cause the same 'bouncing' behaviour: watch face->app view->watch face, rather than watch face->apple pay. Some time later, eg, 20-30 min, dbl pressing the side button opens Apple Pay again.
Attempts to fix the problem have included: restarting the watch, unpairing (ie, erasing the watch) and re-pairing, calling Apple Support multiple times all to no avail. Does anyone know what the resolution is? Apple Pay on my iPhone 11Pro works fine.
Apple Watch Series 8, watchOS 9