I installed package of network-manager 1.10.14-0ubuntu1 from bionic-proposed, and can confirm that version fixed dns leak: now when vpn connection established it gets `DNS Domain: ~.` in systemd-resolve automatically, so no more needed to manually apply command `systemd-resolve -i tun0 --set-domain=~.`. This positively fix dns leakage, verified by dnsleaktest.com
I installed package of network-manager 1.10.14-0ubuntu1 from bionic-proposed, and can confirm that version fixed dns leak: now when vpn connection established it gets `DNS Domain: ~.` in systemd-resolve automatically, so no more needed to manually apply command `systemd-resolve -i tun0 --set-domain=~.`. This positively fix dns leakage, verified by dnsleaktest.com