https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can#w_ipv6 https://support.mozilla.org/en-US/kb/firefox-cant-load-websi... Not s

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can#w_ipv6 https://support.mozilla.org/en-US/kb/firefox-cant-load-websi... Not sure if this is what you're experiencing but I don't have IPV6 and this was causing a number of issues for me. Firefox has been so much better since disabling this.