If you are one of those that like to play around with Firefox settings, you should be aware about DNS-over-HTTPS (DoH). At this time, DoH should remain disabled which is the current Firefox default setting. Otherwise, some common "andrews.edu" URL’s would not work properly.
When you type a web address or domain name into your address bar (example: www.mozilla.org), your browser sends a request over the Internet to look up the IP address for that website.
Traditionally, this request is sent to servers over a plain text connection. This connection is not encrypted, making it easy for third-parties to see what website you’re about to access.
DNS-over-HTTPS (DoH) works differently. It sends the domain name you typed to a DoH-compatible DNS server using an encrypted HTTPS connection instead of a plain text one. This prevents third-parties from seeing what websites you are trying to access.