Mozilla has introduced a mechanism to let Firefox browser automatically fix certain HTTPS errors. Antivirus software often tries to intercept HTTPS connections on Firefox. Starting with Firefox 68, the browser will automatically enable the “enterprise roots” preference and retry the connection whenever it detects a “Man-in-the-Middle” error. Mozilla only trusts those CAs that are listed in its own root store, so antivirus products relying on other trusted CAs provided by the operating system (OS) are not allowed to intercept secure HTTPS connections.
Source: https://thehackernews.com/2019/07/firefox-https-security.html