Elitebook 1050 G1 hangs after display turns off when connect to docking

[DaIceMan]

After some Windows 10 update about 2 months ago my Elitebook 1050 G1 (with all the latest INTEL and NVIDIA VGA drivers) will hang after the display turns off (no standby) when connected to my Thunderbolt Dock G2 and E273q monitor. The display will turn off after the specified timeout but will not turn back on when I move he mouse or touch the keyboard. If I disconnect the USB-C connectot and open the laptop lid the screen will stay black and the laptop fans will spin up to max. There is no other way to recover this other than to press the power on for more than 10 seconds and kill the power. The funny thing is that if I press the standby button from the keyboard while connected to the docking station in this state (black screen), the laptop will enter standby and it will also turn back on when I move the mouse or touch the keyboard, however, the screen will stay black and the laptop will be unresponsive. I have tried using the DDU utility to wipe the NVIDIA and INTEL drivers clean from the system and re-installing older versions from HP of these but the issue persists. I have the latest Thunderbolt Dock G2 firmwares installed. I have seen several others having similar issues and some have resolved them by installing an older version of the INTEL video driver (25.20.xxx) which I have tried to install again without solving anything.

It appears that if I leave the laptop sitting with a black screen for about half an hour, it eventualy *does* recover, but this is unacceptable. It seems to be a stuck handle/driver issue which after it times out recovers - possibly the dual NVIDIA/INTEL setup which this laptop has. Any suggestions are appreciated.