Hi!
I had same kind of problems with Windows 10 1903. Strange sound distortion and all kind of crackles everytime when I recorded my set to USB through USB port 2. I downgraded my computer to 1803 and all problem are gone. I'm using xdj-rx2 with latest firmware version 1.37 and latest usb drivers. First I thought there must be some sort of problem with my rx2 or USB cable, but finally older version of Windows 10 solved all the problems. Now I have disabled all update features and I stick to this version. You should try it aswell. Good luck!