I had this same issue!
I was pulling my hair out trying to get the cam link to work.

I kept reading about the root hub not having enough bandwidth.

Here is what i did to fix it!
I bought a usb 3.0 pcie card like the one here:
https://www.amazon.com/Express-Expansion-Controller-Rosewill-RC-508/dp/B011LZY20G

I hooked up the camlink to one of the new port and now it works flawlessly!

​