I have a similar issue:
My app consists of 2 containers (Python backnd and nginx with flutter UI) in the same network build and deployed to a web app using docker-compose.
Locally, these communicate with each other without any issues.
In the Web App the backend cannot be reached. The error indidcates a need to use https, but as I am simply trying to reach a container service at http://<container_name>:8081 I struggle to understand, why https is requested.
Beyond that I have attempted to deploy the same app to a VM. Similarly, the UI cannot reach the backend throwing a different error: XMLHttpError: ERR_NAME_NOT_RESOLVED.
My assumption is that the netoworking inside the web app and the VM is somehow different to my local environment prohibting these connections.
I do not expect it to be identical. At the same time, my app is very rudementary at this point and it seems reasonable to expect that the default settings would work.
I am grateful for any adivce as I am relatively new to Azure.
Thanks!