On 2/4/21 1:30 PM, linux guy wrote:
> I am now logged into my plasma session using a wired keyboard and a
> wired mouse, using USB ports that were not previously used.

sounds more of a usb port or bus issue.

The keyboard and USB port worked fine during boot up. I was able to edit the kernel command line in grub without any issue.

This is not a hardware issue. Something changes in the software during the boot process.