Telemetry link not working!

Herelink is unable to establish communication with the Flight Controller (FCU) module.
I have also observed that the video streaming and the analog controls are still working ( FCU is able to receive control signals from the Herelink joystick module.)
I have tried with multiple Flight controller units, but could not find the actual cause of the issue
Please guide me on how to proceed with the issue.

Please verify the telemetry cable. This is what cause the problem most of the times.
Also make sure your units are updated at latest stable. A bug with similar symptom was fixed in recent version.