Event Grid - Logic Apps - Could Not Retrieve Values

Question

I'm attempting to work through this

I created service principal as per this

Granted the service principal Contributor on the subscription.

When I go to the Logic app, the connection using the service principal succeeds, I

1. select "When a resource event occurs"
2. select my subscription
3. select GridTopics for resource type
4. the resource name pull down errors out "Could Not Retrieve Values"

Answer 1

Apparently I just need to give Azure time to connect the dots....