I am running the 10.3.0 Docker container version. Everything is working great except that within the web user interface, the WebDav url is showing the hostname of the container host. I am using a reverse proxy to route traffic to the container on the specified port so the hostname being displayed in the web interface is not correct.
i have put the word “proxy” into the search box on https://doc.owncloud.org/server/10.3/ and found the following documentation immediately. Maybe this helps you to configure ownCloud for your proxy environment?