Comment 6 for bug 1813742

I can confirm I'm having the same problem with a Dell Precision 5510
laptop. I have traced the problem to the startup item
"/usr/lib/x86_64-linux-gnu/cinnamon-settings-daemon/csd-xrandr" it seems
xrandr is freezing the system when it boots up connected to a Thunderbolt 3
Dock.

If I disable that startup item, I can boot up while docked just fine, I
just can't change my monitoring configuration around. If I boot up using
the 4.15.0-43-generic kernel, that startup option works just fine and
everything works.

Somehow linux-image-4.15.0-44-generic has changed how the video card works
with Thunderbolt 3 docks and as soon as xrandr tries to fully initialize
the graphics cards everything freezes up.