I’ve just added an onPress handler to a Banner in my POS UI extension. The action appears in the Banner with the correct text (as specified by the action prop), but when pressed, it simply invokes the default action of hiding the banner, and my onPress prop does not get invoked. I’m using @shopify/ui-extensions-react version 2024.10.2.
This has also been raised recently by another developer in the Shopify Partners Slack (link).