I've decided to try that Mullvads PUBLIC encrypted DNS server/s, and wasted about one hour of my time. Firstly, I've followed the directions from Mullvads' web-site how to install it on Firefox. NOTHING worked! Secondly, I've decided to enter the Mullvads DNS server into my AdGuard DNS settings list and followed the directions provided by the AdGuard web-site. My AdGuard got stuck (got hung). The only one way to get rid of my hung AdGuard was to uninstall it and re-install it again. I think Mullvads is too small to advertise their PUBLIC(!) (and free-of-charge) DNS servers. "Mullvad's encrypted DNS solution is available free of charge for everyone."
Sorry, but I've used Mullvad's public DNS servers just fine. There were no issues. So, the error is not with their servers. Also, why are you messing with anything related to an extension for DNS servers. That's dumb. The common denominator here is you and user error. Either change your adapter DNS, or change the DNS used on your router, and be done it,
From Mullvads' instructions (that I've tried and it did not work!) Firefox (desktop version) Click on the menu button in the top right corner and select Settings. Click on Privacy & Security in the left column. Scroll down to the bottom. Under Enable secure DNS using select Max Protection. Under Choose provider click on the drop down list and select Custom. In the text field that appears, paste one of the following, then press Enter on your keyboard. https://dns.mullvad.net/dns-query https://adblock.dns.mullvad.net/dns-query https://base.dns.mullvad.net/dns-query https://extended.dns.mullvad.net/dns-query https://all.dns.mullvad.net/dns-query Next, I've tried to use Mullvads' DNS with my AdGuard desktop app - DNS Protection - and it did not work properly!
The word install made it seem like you were using an extension. However, I am literally use Mullva's DNS in Firefox right now and it does work as expected. Do you have another DNS address in your router, tap, or in Adguard?
I've checked and Mullvad's DNS works on Firefox 115 (ESR) executed inside openSUSE Leap without issues @zmechys maybe local AdGuard is somehow messing with Firefox DoH settings?
I've turned off AdGuard and started using (without any issues) Mullvad's DNS servers. Just a question. Cloudflare Browser test shows that I don't have "Secure SNI." With Cloudflare DNS servers I have "Secure SNI."
