Cintiq 27QHD Stops Mouse/Keyboard From Working

I have a 27QHD that was working on my old Windows 10 (64-bit Home)machine but when I added it to my new Windows 11 (64-bit Home) system, it causes the mouse and keyboard to stop working after about 10-20 minutes.  The machine is still running (as shown by Task Manager), but the lights on the keyboard and mouse go out, and they are unresponsive.  Unplugging the USB connection to the 27QHD and restarting the computer gets everything operational, again. 

This machine ran fine for about three weeks without the Cintiq attached, and it has run fine for a couple of days after I unhooked the Cintiq.  When the Cintiq is first attached everything seems to run fine on both the PC and the Cintiq, until the keyboard and mouse stop working after 10-20 minutes.  It always stops working, no matter if the machine is just sitting there after a restart, or if I've been using the mouse, keyboard, and/or Cintiq.  Without the Cintiq attached, there has never been a problem.

The machine is running an Intel Core i9-14900K with 32GB of RAM and a GeForce RTX 4090 video card. In addition to the Cintiq, I also have an MSI MAG401QR monitor attached to the video card (both are attached via HDMI connections). The Cintiq is attached directly to one of the motherboard's USB ports. I haven't tried running the Cintiq without the Expresskey dongle, btw. Any ideas would be most welcome. Thanks! -Schuyler