Only four keys of the numbers above letters working and RHS numeric keys not working with passcode entry

Using Windows 11 - All of a sudden the top numeric keys and symbols are not working on the Vostro keyboard.  The numbers and symbols corresponding to the 5,6, %,^ and -,=,_,+ are working but all the other keys are not.

The RHS numeric key board IS working UNLESS I have to enter a passcode numeric e.g. for bank account, dell login passcode etc...

I have googled the problem and tried the following:

- reinstalling drivers, going into EASE of ACCESS and turning off "Turn on Mouse", pressing num lock, FN etc...

If I plug in an external keyboard, I am able to use the numeric/symbol keys above letters without a problem.

Any ideas - is it a hardware failure?

Thanks - Annie