I had a similar problem when 2 ASI cameras were attached (one 120MM for guiding and one 174MCPro or 533MCPro for imaging). But now I connected my complete hardware via a USB-Hub too but currently I use a Starlight Lodestar for guiding and this works fine for me. I had some issues to connect the ASI camera via Pegasus Astro Powerbox Advanced, maybe this is cause by the USB-Cable.
Ia have the feeling that the original cable works best.
Maybe you should try to connect the camera step by step directly via USB-Port and then switch to the HUB.