Steinberg UR22 - HI-Z (No sound)

Hi everyone!
I write this post because I have a problem.
The problem is that when I connect my guitar in the Input 2 of the interface, it sounds correctly, but when I press Hi-z button the sound of the guitar disappears, there’s no sound from the guitar, but when the Hi-z botton is not pressed it sounds.
(Sorry because of my english :slight_smile: )