Pre-flight checklist--Radio Control: No signal or invalid autopilot-RC config

Pixhawk
1

Have a good day!
The radio calibration was successful during vehicle setup. However, the pre-flight checklist shows that radio control has something wrong:

Radio Control: No signal or invalid autopilot-RC config. Check RC and console.

I am using QGroundControl and the airframe is VTOL DUO Tailsitter. The receiver was connected to the RCIN. Did I miss anything? Thank you very much for your help.