Explanation
According to the VMware Carbon Black Cloud Sensor Installation Guide, the port that will be the fallback if the VMware Carbon Black Cloud sensor is not able to establish connectivity to the VMware Carbon Black Cloud Content Management URL over the standard SSL port TCP/443 is TCP/8443. This port is used for content management fallback, which allows the sensor to receive instructions (manifests) that configure a wide variety of the Carbon Black Cloud features and their underlying rules. The sensor will attempt to connect to the Content Management URL over TCP/443 first, and if that fails, it will try TCP/8443. If both ports fail, the sensor will not be able to communicate with the Carbon Black Cloud console and will not receive any policy updates or commands1.
The other ports are not used for content management fallback. TCP/54443 is used for Unified Binary Store (UBS) fallback, which allows the sensor to upload file metadata and content to the Carbon Black Cloud for analysis and reputation. TCP/80 is used for third-party certificate validation, which allows the sensor to verify the communication certificate with the Carbon Black Cloud backend. It will not fallback and fail is not a valid option, as the sensor has a built-in fallback mechanism for content management1. References:
Configure a Firewall - VMware Docs, Ports and URLs table.