It used to work. Recently, however, if I reboot the thinkpad in the doc, I lose the two DP external monitors.
I.e. the machine boots on internal display, and if I go to windows "screen resolution" I can see the names of the two external monitors greyed out with the wrong resolution.
If I do a WINDOWS-P, then extend to the second one, then make the third the "main display", then disable the internal panel, Im back to where I should be. If I sleep and wakeup, it keeps the arrangement. If I dock the notebook while running, it automatically jumps to the correct arrangeement (i.e. internal panel off, two external displays extended).
Its only if I boot when in in the doc it fails, and I ahve to wait for 5 minutes fo tthe machine to boot, then faf about for another minute to get the displays working. I have never had this problem with Dell laptops in docking stations with external displays.
I dont expect a solution - and I accept im probably the only person who gets this error.
The machine cant reboot (I can only shutdown and cold boot) since I enabled password protection for the HD in the bios, so I cant test that.