Publish to AWS: I could not deploy to an existing cloud app

In Publish to AWS, the Existing Targets list did not show my project. I expected to see it there.

Just set image tag as "latest" and point to ECR browsed from the list myapp.api (is the name)
Toolkit: 1.43.0.0
Visual Studio: 17.7.6

Start with the Publish to AWS Existing Targets flow and reproduce the report using Toolkit 1.43.0.0, Visual Studio 17.7.6, the latest image tag, and the ECR target named myapp.api. Trace why the existing project is omitted; done means explaining or correcting that discovery behavior and verifying the project appears when eligible.

Written by the indexing model from the issue text.