Docker-compose installation problem - 'bad host' from web server

I’m following the docker-compose installation.

All of the docker containers are running, and I verified that the host name in the config files matches my hostname.

When I connect to the web server, I get ‘Bad Host’.

The log file from the traefix container is:

“GET / HTTP/2.0” 500 9 “-” “-” 1 “hostname-checker@file” “-” 5ms

Any hints?