Express Transit Card stopped working on Apple Watch

For many months I was successfully using my Apple Watch to pay at public transit gates & pay terminals, using a specific transit card loaded to Wallet. This stopped working a few weeks ago. The IOS on my watch is up to date and I tried removing and re-adding the transit card to Wallet in the watch app. Neither of these solved the issue. I'm able to successfully pay with the same card using my iPhone at the pay stations. Does anyone know how to solve this so I can start paying with my watch again?