Can't change Express Transit Card

I am having trouble changing my Express Transit Card on my Apple Watch Ultra. On my phone, it is properly set to the card I want to use. But on my watch, it is set to another card that I have stored in Apple Pay. When I try to change it, either in the Watch app on my phone, or on my watch itself, it will not change.

In the app on my phone, when I try to change it, I select the card I want to use, and then it asks me to enter my passcode on my watch. I do so. Then, after the wheel spins a moment on my phone, it tells me "Could Not Connect to Apple Pay: Make sure you are connected to the internet." I am definitely connected to the internet on both my phone and my watch.

If I try to change my Express Transit Card on my Watch, in Settings, it asks me for my passcode, then spins for a moment, then goes to a screen where I just see the time, in digital format, very mimimalist, and then does nothing. If I move my wrist, I go back to the Express Mode screen, where I can try again to select the card I want to use.

Both cards are in my Wallet on both my phone and my Watch.

Why can I not make this change on my Watch?