Ah, I forgot to mention I've found a somewhat working workaround. If you uncomment the line "DNS" in /etc/systemd/resolved.conf and put list of DNSes with first VPN's DNS then your normal DNS, then it will always try to go through the VPN's DNS first even if you're not trying to access a resource from the VPN. Be careful not to type any dangerous domain names when connected to the VPN though.
Ah, I forgot to mention I've found a somewhat working workaround. If you uncomment the line "DNS" in /etc/systemd/ resolved. conf and put list of DNSes with first VPN's DNS then your normal DNS, then it will always try to go through the VPN's DNS first even if you're not trying to access a resource from the VPN. Be careful not to type any dangerous domain names when connected to the VPN though.