NextDNS with ProtonVPN

Question: I paid for NextDNS and configured it properly and is working fine on my devices. I was able to see all the logs. 

Then I installed ProtonVPN. In ProtonVPN, I used custom DNS server as NextDNS DNS servers. 

But when I login, I see the following message. 

"This device is not using NextDNS.

This device is currently using ”Host Universal Pty Ltd” as DNS resolver."
And also I do not see the logs.
So NextDns is not working. 

Suggest. I want to get benefited from NextDNS adn ProtonVPN.

Or is NextDNS is a VPN and I can cancel ProtonVPN?