Cannot change the RC input driver port

Hello, I’m using pixhawk 4 (firmware PX4 Pro v1.13.0) and QGroundControl v4.2.3. As a receiver for RC i have Happymodel EP1 RX 2.4G ExpressLRS which is connected to TELEM/SERIAL 4 port.
And in this setup RC doesn’t work.

I have checked in MAVLink console rc_input command. And it shows that PX4 uses another UART than i have selected in settings:

And if i change the UART port in console by myself it works fine.

But if I reconnect PX4 the problem occurs again, so I need to reconfigure UART port in console every time I power up PX4.

So the question is: Why RC_PORT_CONFIG parameter doesn’t work properly as I’ve configured it to TELEM/SERIAL4 port?

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