Debugging DNS
My main tools to debug DNS (I don't use dig it is such an unfriendly tool)
https://dns-lookup.jvns.ca [github] is a simple web-based DNS lookup tool.
curl has a resolve flag allowing you to bypass DNS lookup and verify that the HTTP server sends a valid response.
# HTTPS Example
curl -I -L "https://example.org/" --resolve example.org:443:93.184.216.34
# HTTP Example
curl -I -L "http://example.org/" --resolve example.org:80:93.184.216.34