I have two setups, both with Klipper/moonraker/mainsail/fluidd. Version 5.1 DOES appear to use any form of DNS lookup that kills any VPN setup. However, I can use the IP address and the manual port number.
The manual port number is the only way it will find and test any Klipper setup. Auto seems to ignore the port ranges for Klipper.
DNS entries for vpn or even .local entries also fail hard. Very poor because the IP can easily change. it should be able to use things like mainsailos.local
Once a connection is set the only options are add new, delete, and reorder. we should be able to see some details like name : port.