Check for any customizations in /etc/NetworkManager
Alternatively, reinstall surfshark, enable killswitch, connect and disable killswitch before disconnection... When you disconnect it should be fine..
The killswitch is most surely a combination of changes on networkmanager dispatcher script, iptables rules and dns setting (/etc/resolv.conf)
Also, the family still in russia gets some last news about their loved ones and the certainty they are not dead in the battlefield