I tried first to delete my unused Comm Ports. (That didn't work).
I will try your suggestion and post the results later today.
This is what I'm currently seeing in Device Manager:
QDX Transceiver - Other Devices: "The drivers for this device are not installed." (Code 28)"
QDX Transceiver - Sound, Video, and Games Controllers: "This device is working properly."
USB Composite Device: "This device is working properly."
Thanks for your kind and patient assistance!