I am not using a USB hub.
I’m not using Traktor or VDJ with the 8000, I used the DDJ-SX and a MC6000 all with zero issues.
OS 10.11.6 This OS is approved by Serato.
Again, I go back to, $1,300 and I have to spend this much time troubleshooting and picking USB Ports? This makes me even more concerned when I upgrade my Mac and I have to use a USB-C Port.
I recommend opening up your activity monitor when the distortion starts, check if there is anything using drastic cpu. If you see that Serato is running a bit heavy on cpu usage, try adjusting the latency drastically & see if it makes a difference. Also try reducing the screen refresh rate in Serato settings. At least it’ll either eliminate or confirm latency or refresh rate as a cause.