Radio calibration problem using Flysky FS-i6 and pixhawk 2.4.8

Hi all, I’m configuring a quadcopter (Pixhawk 2.4.8) in Mission Planner. I have already installed the firmware, calibrated the compass and the accel, but when it comes to calibrating the radio, I have had problems. It turns out, that even linking the transmitter and receiver and checking 100 times if the receiver is well connected to the flight controller, the green bars don’t light up, they stay empty. I’m attaching a picture, and I would be very grateful for any help.