I am using the same domain name for DSM, Bitwarden and may other local services. They all just run on different portsGood point here from @one-eyed-king, I did not notice you tried to pass http resquests to you https port in this declaration.
One more question : are you using the same domain name to access DSM and Bitwarden ?
If so, that may explain why you can't access DSM anymore once you have this custom config file activated.
It will redirect anything that has
mydomain.netto what you have set in this file.