Thunderbolt Display Hotplug

I have a MacBook Pro 11,5 running Ubuntu 16.04.

I have attached an Apple Thunderbolt Display to it. I have noticed that the display only works if it was plugged in on boot. I can see the display in the display manager and in xrandr:

DisplayPort-2 connected (normal left inverted right x axis y axis)
   2560x1440     59.95 +
   1280x720      59.86

If I restart the machine with the Thunderbolt Display plugged in, everything works just fine, I can use the external display. However, if I then remove the Thunderbolt connector and then reinsert it, I cannot activate the display.

Interestingly enough, ethernet works fine on hotplug, and the display does show up in xrandr as demonstrated, but I cannot get the display to activate.

Wasn't Thunderbolt hotplug fixed in kernel 3.19?