Cannot stop mix release

I found this thread: Cannot stop Mix release of my Phoenix app with no solution, so I’ll try a new thread instead of revoking the old one since it may or may not be related…

I can start the application with bin/app daemon. After that it is visible in ./erts-11.1.3/bin/epmd -names:

epmd: up and running on port 4369 with data:
name app at port 51517

The release cookie is set to a random string and present.

When I now try to run ./bin/shop pid or ./bin/shop stop it will fail with --rpc-eval : RPC failed with reason :nodedown.

Maybe relevant: I’m running the release from the home directory of a user who was specifically added to run this application (i. e. not as root).

Edit: Never mind