The docker engine runs as root. Adding an unprivliged user to the docker group, and therefore allowing it to access the docker.sock to interact with the docker engine, doesn’t change that fact…
I am not sure what I am seeing, unless I see the output of docker ps -a. It is not possible that two containers with identical container name are created. Looks more like it tries to create the container, but then encounters an error.
Please share the content of your compose file.