I got my XPS 15 9550 with high end specs in August for which I paid a fortune and I have been having screen brightness flickering issue every time I upgrade to the new BIOS which as stated by Dell is an urgent update. The screen brightness starts to flicker every now and then. It is definitely the most annoying thing ever. Every time they release a new update I try to upgrade and see if they have fixed the issue or not but unfortunately, every time I am disappointed and eventually I just roll back to the original BIOS version 1.1.15 which fixes the flickering issue. The sad part is some of the other updates require you to have the latest BIOS in order to upgrade them. Does anyone know when Dell will be actually fixing this glitch?
A new bios update will be available mid-December to fix this issue. In the meantime, adjust your brightness up one level and that should help. Update BIOS to 1.2.18 from Dell website as a long term solution. 1.2.18 is targeted to be available in middle Dec 2016.