Pixhawk 5X (Telemetry 1 not working after update)

Hello everyone!
After updating the firmware via QGroundControl, the Telemetry 1 port stopped working. I connected radio telemetry to it.
Now it works only on port 2.
Firmware - PX4 Autopilot 1.12.3
MavLink writes “No connection” and packets are not accepted.
The green LED on the telemetry itself is on, there is a connection between the radio modules. From the side of the computer, the red LED blinks periodically - data is being sent.
Resetting settings doesn’t help.
Tried different speeds but it didn’t work.

What could be the problem?