Rekordbox suddenly no detect the controller DDJ-400

Hi there.

Since i have purchased the DDJ-400 and used with Rekordbox a strange noise connecting the USB cable to computer is output in the speakers, so, i punchased this cable and and usb adapter (500mA)

Now the noise dissapeared!, but, Rekorbox sometimes invite me to purchase a license (this is wrong, i have hardware unlocked)

And the most strange problem is DDJ-400 disconnects in the middle of a session, stopping the recorded file and the music stops.

I have last firmware installed 1.03 and using Windows 10 completely uptated with last Rekordbox session.

How i can solve the problem?

Tnx for reading