The panel USB should be just a USB extension cable. You may be able to take the extension connection behind the panel and put in a different USB port. That should test either the extension or the port.
Have you contacted Jeff Odum at thestcgroupllc.com? I just asked him about this and he says it is approved under their STC. It may require to work with them. Was your installation done with their STC?
It is my understanding that Dynon has recently opened up full integration of the Trio AP to its interface. You may want to contact Trio to see how to get your AP configured to communicate to the Dynon.