I use a VPN service that is connected to a server in another country, however this VPN service does not offer control over my DNS requests to block some sites so I preferred to use another DNS resolver that has this function.
My question is: When I access my VPN’s website, it accuses that a “DNS leak” is occurring. Can the DNS provider know my real IP address, or does it only know my VPN’s IP?
DNS leaks normally occurs when your OS decides to use the wrong interface for DNS queries. It’s not magic, sorry.
There is a decent explanation here: https://www.top10vpn.com/what-is-a-vpn/vpn-leaks/
are you a bot? a traceroute to the DNS would show the wrong interface.
Sadly, I can not explain this to you any better.