User requests improvements for using custom DNS servers with Gluetun, as they are experiencing extremely slow DNS performance when using their own local DNS server.
### Is it a bug? - [x] I know this is an issue with the app, and contacting Mullvad support is not relevant. ### I have checked if others have reported this already - [x] I have checked the issue tracker to see if others have reported similar issues. ### Current Behavior I'm trying to use my own local DNS server running Pi-hole - and while it does work with the Mullvad VPN app's custom DNS server and local network sharing settings, the DNS performance is abysmal. It takes several seconds to connect to anything for the first time - and even reconnecting to the same website is still pretty slow. It has the tell-tale failure mode for slow DNS where the browser hangs when loading a site, before suddenly pulling in everything all at once. On occasion the DNS is slow enough to time out entirely and force a page reload - which usually works. ### Expected Behavior Using the same DNS server without running the VPN performs fine - I would expect that using my local DNS with Mullvad VPN