If the callback shows connected, it means the bridge is correctly instructed to send updates to HA. So it must receive the updates of the sensors.
The notification of the callback appears only when the Nuki Card modifies the callback configuration of the bridge, if the callback sensor shows connected, it won’t need to do any modification because it’s ok.
This is good.
The bridge has a hw/sw limitation of processing only 1 connection, if you use the Nuki Card you should avoid using other apps that communicate with the bridge, Nuki Mobile app included, otherwise the bridge will reboot or give errors 503.
So when you test the Nuki Card, make sure you disabled/uninstalled the HA official integration, and close the Nuki Mobile app on the phone.
When you open the door, the bridge executes the callback configured in its list, in your case it will send the update to HA with that webhook. So make sure the webhook token in HA is the same you configured in the secrets for the bridge. If it is the same, you MUST see instantaneous update of the door sensor on the card. If you don’t see it, the token or the url or something else is wrong in the configuration. Nuki Card is used by many users, and these basic things are know to work reliably.
Let me know…