You manually configured your VPN connection: If you have set up your own VPN connection, there is a much higher risk of DNS leaks if the DNS settings are misconfigured. An intruder controls your router: If you are using public Wi-Fi, an intruder could trick your device into sending its DNS requests outside the encrypted VPN connection.

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DNS over HTTPS (Your Handy Guide) | CactusVPN

DNS and Mobile VPNs - WatchGuard For example, if you specify the DNS server 10.0.2.53 in the Network DNS/WINS settings, mobile VPN clients use 10.0.2.53 as a DNS server. If you have a local DNS server, it must appear first in the list. This is required so that local domain resolution works for mobile VPN users. VPN Service Vs Smart DNS Proxy

How to configure smart DNS proxy on a DD-WRT router

Jan 22, 2020 Top 16 Best Free and Public DNS Servers in 2020 | VPNpro