X1 Yoga and Thunderbolt 3 Gen 2 dock

[cpfuller]

I am having an issue with my X1 Yoga and my Thunderbolt 3 Gen 2 dock. For years I only connected the computer to the dock when the laptop was off and the dock was off. As an experiment I decided to start hot docking and undocking the laptop. (I was told that this was possible by a Lenovo Tech). I can report that this seemed to work extremely well right up until it didn't. The problem I am now having is the dock will no longer start the computer when they are both off. It will turn on but it hangs at the Lenovo bootup logo, on the 3 desktop monitors, and stays their. I have all of the latest drivers and bios updates installed. If the laptop is on when it is connected to the dock it will function properly and connect me to the 3 monitors and all of the peripherals when I unplug it from the dock everything works as it should again.

Any help is greatly appreciated.

X1 Yoga 3rd Gen 20LD0017US, Windows 10 Pro, 16gb ram

Thanks
Charles

[dr_st]

Try to see whether one of the monitors / other peripherals connected to the dock is the culprit. That is, try to disconnect everything except one monitor / keyboard / mouse, and see if it works. If so, then experiment with connecting other devices, one thing at a time.