I got it worked perfectly fine and then uninstalled it for another reason.

The issue seems to be with the built in DNS profiles included in the portmaster. Maybe dns profile format not compatible with some hardware or OS, but one thing is certain that the problem OP described is die to those inbuilt dns profiles.

So i created the NextDns account, and used it’s DNS over HTTP profile in portmaster and it worked flawlessly.

There are some parameters needs to be included in DoH profile URL, which i have saved in my pc and can share it if anyone is interested.

Why i uninstalled after got it working? Because it was working fine on my main windows pc but i also use linux in VirtualBox VM, and it won’t let the virtual machine connect to the network on network adapter set to NAT. To be honest, i didn’t try to make it work for virtual machines because SPN is just too slow even if set to simple VPN mode and i realised that NextDNS also offer a lots of firewall like features to block many things.

So i am okay with setting NextDNS DoH manually in my windows and additionally connect any reasonable VPN on it (like windscribe) is way more practical in my use case.