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 Dell laptops and Thunderbolt 3 docks; as soon as xrandr tries to fully initialize the graphics cards everything freezes up. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1813663 Title: External monitors does not work anymore 4.15.0-44 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1813663/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
