@Adrian, thanks for reporting this problem. I think I understand the root cause (which was my backlight fix for the 780p XPS13 models). On your 1080p XPS13, please run the command "apport-collect 1169376" in a terminal window, which will capture the hardware profile of that model and post it to this bug report. I'll use that data to work on a fix which doesn't break the 1080p model.
@Adrian, thanks for reporting this problem. I think I understand the root cause (which was my backlight fix for the 780p XPS13 models). On your 1080p XPS13, please run the command "apport-collect 1169376" in a terminal window, which will capture the hardware profile of that model and post it to this bug report. I'll use that data to work on a fix which doesn't break the 1080p model.