I have a 13" macbook pro running mojave 10.14.2. I generally use my laptop in closed lid mode connected to the TBT3-UDV dock (which itself connects to an external monitor and USB mouse and keyboard and so on). When I restart my machine with the lid closed, the screen stays blank.
When I’ve tried restarting the laptop when it is open, I have noticed that the monitor and hub don’t seem to be connected until I log in. (In addition to the screen staying blank, the external mouse and keyboard don’t work.)
After I log in, everything works fine. I can close my laptop and/or disconnect and reconnect the cable and the mac recognizes these changes.
Is there a way for the dock connections to work after a restart, without me having to open the lid and log in using the laptop keyboard first?