Switching your card when using Apply Pay as part of checkout on website was better when tapping the card icon allowed you to switch the card you are paying with but since iOS 26 that is for editing your billing address… if you want to change the card you have to select option below that with no icon titled “Other Cards & Pay Later Options”
Speaking of that, sometimes I touch the card I want and it doesn't select it. I go through this dance of touch, wait, touch, wait, repeat. Insane.