PX4_INFO() message is not shown

I am working with the pixhawk4.

I modified px4_simple_app to print message “Hello Sky!” continuously.
I have built px4_simple_app, and I succeeded to run on the QGC MAVLink console.
With this condition, I can see “Hello Sky!” message on console.

But I cannot see the message if I added px4_simple_app to rc.board_defaults to run it from the start.

Can anyone help me about this ?