Keyboard A1243 not recognized on Mac Mini late 2018

This was posted in late October by user razvangeorge in https://discussions.apple.com/thread/250773700. Support posted the basic instructions on troubleshooting a wired keyboard - I'm here to tell you that doesn't work.

System Information doesn't even show the keyboard in the USB device list when the keyboard is plugged in. I can use a Saitek Gaming Keyboard Pro in any of the USB ports, A & C (w/adapter), and have it work instantly. I've tested the keyboard on other Macs (MacBook Pro 2018, Mac Mini 2012) with no problems. I've tried another A1243 on the 2018 Mac Mini and gotten the same problem. I've reset PRAM & NVRAM. No joy.

I'm going to stay on 10.15.7 Catalina because numerous app packages I'm still using may not work.

I can provide system logs as needed.