A top-down routine for any "my container is not working" moment: status, logs, config, inside, network, resources. Work down the list and stop at the first thing that looks wrong.
Status: docker ps -a. Is it running, restarting, or Exited (code)?
Change one thing at a time and note what you changed. Most "mysteries" are a stale image (forgot --build), a wrong env var, or a service not on the same network.