There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connection certificates and send their own.

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites

https://support.mozilla.org/en-US/kb/secure-connection-failed-firefox-did-not-connect

https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors

What do the security warning codes mean

"You don't have permission to access the requested URL on this server. Reference: 18.84e4317.1650916378.518b3b92"

This message is characteristic of a Web Application Firewall, a layer of protection large sites use to avoid denial of service attacks and other suspicious, bot-like traffic.

It can be based either on your IP address -- sometimes an address or range of addresses will be blocked temporarily -- or on unusual characteristics of your browsing requests. So you could:

• if you are using a VPN or proxy, trying changing your server (exit node) to get a different IP address
• if you have use any Firefox feature or add-on to modify requests -- for example, blocking more cookies than usual, suppressing the referring site header, modifying the user agent, etc. -- try setting those back to normal