With the most recent updates of Firefox with secure server substitution, I often open the Firefox browser for windows and cannot even reach an initial page because reaching the secure DNS substitute servers (Cloudfare) is failing. The NextDNS server also does not work. I love this security but it appears something is wrong. I have long been using Cloudfare as my listed DNS sever on my router for the entire home LAN, but now it is not connecting by that or by Firefox (and Waterfox) - and this includes using Google and a few other major DNS alternatives , but the Chrome browser, I keep as a backup, works. Moreover, I have had to swap my default DNS on my router and in windows to be my local Spectrum (Charter) DNS servers 71.10.216.1 & 71.10.216.2. They always work when I turn off all Firefox securre browsing settings for DNS and HTTPS. I WANT THOSE PROTECTIONS FROM FIREFOX, BUT I DO NOT KNOW HOW TO MAKE THIS WORK OTHER THAN TURNING ALL SECURITY OFF!!