So - I continually find that notifications stop working from HA to my iphone. I have have several automations which send notifications and after a few days of working - it stops. I have tried resetting the Push ID and it never helps. Only solution is to delete the device from integration and re-add it. Possibly relevelant: I am using the beta iphone app
Do you have more than 1 device with the same name? It’s possible they are fighting; the mobile_app integration doesn’t handle this well. It’s also worth checking if you are seeing any error logs for the notify service calls. Also check the event log in the app to see if it’s getting any errors around its Webhook, which may indicate an issue with the integration.