To test this, boot into your BIOS/UEFI boot menu and choose to run a full hardware diagnostics test suite, assuming your computer has such an option from the factory.
I make a USB keyboard device called the 'Computa Pranksta' and sometimes have a similar problem.
Only do a hard reboot if this soft reboot sequence first fails. So, when you press that key your computer will restart. I don't remember where I learned this, but I read it from someone else years ago on Ask Ubuntu or SuperUser somewhere.
Note that on some (many?) laptops/keyboards,the PrScr button may require your Function key, Fn, to activate it, so you may have to hold down Ctrl + Alt + PrScr + Fn instead, while typing the REISUB reboot key sequence. Hold down Ctrl + Alt + PrScr, then press the following keys one-at-a-time while holding those first 3 keys down the whole time: R, E, I, S, U, B. I don't know how to really solve the problem, but remember: before you hold down the power button to hard reboot, you can always soft reboot with this funky sequence:
