My Dell Latitude E7470 was affected as well. When connected with my external monitor, Ubuntu would freeze on startup after entering my full disk encryption password, showing the dark-purple screen with a mouse indicator that would not move. When locking my screen, it would simply stay black.
The update to 4.15.0-45 seems to have solved the problem.
My Dell Latitude E7470 was affected as well. When connected with my external monitor, Ubuntu would freeze on startup after entering my full disk encryption password, showing the dark-purple screen with a mouse indicator that would not move. When locking my screen, it would simply stay black.
The update to 4.15.0-45 seems to have solved the problem.