When you say you connected the PC to the mount with USB3, are you saying you connected the PC to the through-mount cable? The CP5 can only use a USB2 cable, since USB3 will not fit in the receptacle.
I am interested in trying to replicate as close to how you experience it as I can. If you are willing to spend some time with me working on the issue, I would really appreciate it. I want to find a solution to the issue.