Problems using RX2 as laptop soundcard

I'm using a Macbook pro 2017 with High Sierra, ( but it does it in Sierra too)

When in System Preferences I used the RX2 as my soundcard, first I hear a weird white noise sound for about 2-3 sec and then the RX2 is setup as my soundcard (outputs the laptop sound) but when I try to play some songs in itunes ou everywhere else after while the sound start to bug as if iwas apply a bad delay FX on it with kind of a reverb and it goes louder and louder until I switch to my internal laptop speakers then it stops.

Also another strange bug, its with video on a browser, like watching a youtube video I hear de sound but the image stops after 5-10sec into the video. And when I unplug my RX2 the video goes back to normal with good image and sound.

Is there any way to solved this?