Are these docs still up to date? In order to get this working, I had to (1) explicitly connect on port 8008 from the Try Me Publisher; and (2) publish the port 8008 when registering, e.g. the command:
docker run -d -p 8080:8080 -p 55555:55555 -p:80:80 -p:8008:8008 --shm-size=2g --env username_admin_globalaccesslevel=admin --env username_admin_password=admin --name=solace solace/solace-pubsub-standard
Port 80, which appears to be the port that we intend to use when trying it out, did not work even when specified explicitly.