I will assume then that when you "search on 'Google'" you actually mean visit your App Engine application via your
custom domain.
If this is the actual issue where you only see the message "domain is no longer parked by GoDaddy" when visiting your App Engine application, than the issue is due to remaining DNS servers on Google Domains or GoDaddy that are still pointing to GoDaddy.
- Note that Google Groups is meant for general product discussions and not for technical support. If you require further technical support for configuring your custom domain with App Engine, it is recommended to post your questions to
Stack Overflow using the support Google Cloud tags while following their
how to ask a good question guide.