HP Spectre X360 Convertible KEYBOARD Erratic after upgrade

HP Spectre X360 Convertible (first gen) running on a I5-6200U and Win10Pro-1809 installed. I have tried multiple times to upgrade to newer builds of Windows (most recently 1903 and 1909) and each time, everything appears to be fine, EXCEPT the built-in keyboard is erratic and unusable. (Touchpad works however). Hitting any key on the internal keyboard creates a "keystroke" and I see something happen on the screen, but by the time I release the key it is subsequently erased or interpreted as a control character or Fn key or something strange. It appears to bring up a dialog box or other artifact.
Going back to Build 1809 resolves the problem and the built-in keyboard works fine. On 1809, I see the standard PS/2 Keyboard and the HID Keyboard device drivers loaded.

Any suggestions how I could move forward?

See the keyboard manufacturer website for latest driver.

If latest keyboard driver wont resolve the issue uninstall the keyboard driver from Device Manager and restart your computer to let Windows 10 install Windows 10 keyboard driver.

@markharris2000, see this post to see if this helps - https://h30434.www3.hp.com/t5/Notebo...t/true#M245197