Windows 10 Docker Host - Display GUI application from Linux Container
You'll need to set DISPLAY to something other than localhost. The container has its own localhost interface, so your X11 client will attempt to connect to itself instead of to your host.
Instead, you can pass in an IP address of your windows machine's network adapter. The container will be able to connect to that. You'll also need to have your X11 server configured to listen on that interface.