Ah, should have checked the connector right away. You are using a baseUrl that does not comply with the app descriptor specification:
Description: The base url of the remote app, which is used for all communications back to the app instance.
The baseUrl must start with https:// to ensure that all data is sent securely between our cloud instances and your app.
Your baseUrl value http://ip-172-31-41-3.ec2.internal:3000 is neither secured by HTTPS nor publicly accessible in the first place (as the name suggests, that’s a private DNS hostname only resolved internally within EC2), so fixing both should address the respectively accurate error message.