Windows 10 Update Issues

It appears that my Precision Workstation is no longer supported under Windows 10.  I used to have support last year; however, it appears that Microsoft is dropping support for some Dell computers.  I received no notification of this at all, but newer Windows 10 updates fail on my T7600 workstation.  I have the latest BIOS available, and this issue started this year.  The October Windows 10 cumulative update results in a Windows 10 reboot loop failure.  I am suspecting that Dell has ceased collaboration and cooperation with Microsoft for C600 hardware.  This is the only logical explanation for going from zero problem perfect updates last year to failures with the latest versions of Windows 10 this year.  I am still on Windows 1909.  Windows 2004 update absolutely fails.  The Windows 1909 October update also fails in the same manner that the 2004 update does.

Was purchasing a Dell Workstation a mistake?