Laptop keyboard stops working after 5 seconds of disuse

My system board (Dell G16 7620) was just replaced and now the laptop's built-in keyboard stops working in Windows 11 if it is left idle for more than 5 seconds. 

1.  An attached USB keyboard always works fine. 

2. The built-in keyboard works fine in the BIOS- it's only when booted to Windows that it fails. So Dell says it's not a hardware issue.

3.  If I use Device Manager to scan "Keyboards" for hardware changes, the built-in keyboard will start working again, and continue to work as long as I keep using it without a 5-second pause.  If I leave it idle for 5 seconds or more, it quits working again.  

4.  I have tried updating the BIOS. 

5.  I have tried uninstalling the "HID keyboard device" devices from Device Manager and rebooting. 

6.  I have checked for updated drivers on the "HID keyboard device" devices.  It says there is no newer version available.  Current running 10.0.22621.1, dated 6/21/2006.  That seems old and if there is a newer HID keyboard device driver available somewhere I'm happy to try it.

7.  The laptop definitely did not have this probably before the system board was replaced.

8.  The problem also happens in Safe Mode.

9.  I have tried the Dell G16 1Zone Keyboard Firmware Update Utility_V07

Any ideas?