Dell E5470 with Intel HD Graphics 520 - screen goes black when undocked

We have a number of Dell E5470s which have Intel HD Graphics 520 chips. Since upgrading the computers to Windows 10 version 1703 (Creators Edition), when the computers are undocked (E Port Replicator), 99% of the time the built-in display will go entirely black or, black with the mouse pointer flashing. The computer will remain in that state until the computer is re-docked. Once re-docked the computer display will work as expected. This is not an issue when the dock is eliminated; connect and disconnect monitor from the VGA port on the computer.

The laptop has the latest bios (1.44.4), latest video drivers from Dell (21.20.16.4627) and Synaptics VMM3320 MST Hub Firmware (3.10.3).

I have contacted Dell support and they confirmed that this is not a hardware issue. I was fairly certain of that going in since this issue is consistent with multiple E5470s and multiple EPort Replicators and EPort Plus Replicators. Dell support then had me contact the Dell Software and Driver Division and they too said it was not a hardware issue, but would not help me try to resolve this issue or tell me if this was a known issue or if anything was being done to try to resolve this issue.

I would appreciate suggestions you might have to help resolve this problem.

Thanks

Randy