Mojave on 2018 MacBook Pro "losing" display(s)
 

Several times when going into screen lock mode, when I come back and unlock my MacBook Pro, one or more of my 3 external displays will be dark and repeated efforts to get it back fail until I disconnect the display from the StarTech USB dock, turn off the dock, wait a few seconds, turn on the dock and plug the display cord back into the dock.
:mad: This is frustrating to say the least. When this happens the screen arrangement goes completely wrong until I get the missing display active again. I'm running Mac OS X Mojave 10.14.3 and DisplayLink 5.0.1