Docker - ASP.CORE 2.2 application and SSH
You have conflicting startup command definitions in your final image. Note that CMD does not simply run a command in your image, it defines the startup command, and has a complex interaction with ENTRYPOINT (in short: if both are present, CMD just supplies extra arguments to ENTRYPOINT).
You can see the table of possibilities in the Dockerfile documentation: https://docs.docker.com/engine/reference/builder/. In addition, there's a bonus complication when you mix and match CMD and ENTRYPOINT in different layers:
Note: If CMD is defined from the base image, setting ENTRYPOINT will reset CMD to an empty value. In this scenario, CMD must be defined in the current image to have a value.
As far as I know, you can't get what you want just by layering images. You will need to create a startup script in your final image that both runs sshd -D and then runs dotnet Application.WebApi.dll.