The background to this awkward situation is that any mobo USB2 header actually has TWO USB2 ports on it. Of the nine pins, four are +5 VDC and Ground, two are the + and - signal lines for ONE USB2 port, and two more are the signal lines for the other port. Very unfortunately with many devices that use a direct cable to a mobo USB2 header so the device can communicate with software running on the mobo, that cable occupies all the header's pins BUT uses only ONE of those ports; the other port is ignored and NOT available! Ideally we would need an adapter that converts the mobo single 9-pin male header into two such headers, BUT also changes the connection of the two signal lines from Port #2 to the correct locations on the second output 9-pin "header" so that they are on the SAME pins as Port #1 should be. If we had that, EACH of the two output "header" connectors would provide a USB port #1 for use with a cable that can only connect to the Port #1 lines. Then each such cable could have its own separate and functioning USB2 port. When I look at the USB2 header converters, adapters and Splitters, I cannot tell whether any of them do exactly this job. If it merely connects both of its output male "headers" exactly in parallel to the host mobo header, that does not give the separation needed.
A few of the devices sold by Corsair include a solution for this: the box has its own USB2 "replacement" header ports so that you can plug in another cable to these. Beyond that, my only idea is to use a converter like this
https://www.newegg.com/black-wavertec-6-10-others/p/181-000J-00065
that converts a mobo USB3 header into a male USB2 header that you could plug such a cable into. HOWEVER, I do NOT know whether the iCue software utility, designed for use with mobo USB2 headers, would ever look for such a communication channel on the USB3 bus.
My best suggestion is to contact Corsair Tech Support and ask two questions:
- Do they KNOW of a USB2 header "Splitter" that separates the two mobo header ports into two separate USB2 header male output connectors so that each has ONE USB2 port on the lines for Port #1, and no connection for the Port #2.
- Instead, can the iCue software find one of their devices on a USB3 header, even though it is intended to work with USB2 headers?
Last option, I suppose, would be to get one of those USB2 Splitter devices that converts one mobo male header into two such headers. Inspect it carefully to see whether it has been wired "oddly" so that each output has the port + and - lines on the SAME pin pair. (I presume that it should be for the Port #1 pair, but it is possible it is the other way.) If not, custom re-wire, following carefully the proper connections for the pins.