GDM breaks output of discrete NVIDIA GPU in Optimus setup
Booting my Laptop (ThinkPad w520) with two monitors attached to the discrete card makes gdm extremely laggy, and causes both monitors to show incorrect or no output, even though they are detected correctly by xrandr and PRIME works (so no issue with the graphics card or driver).
Detaching the screens before boot and only reattaching them when in i3, they work as expected.
Using the ly display manager, everything works as expected as well.
This issue first occurred on Mon, April 27th, but is not solved by downgrading to the date when everything was functional (2020-04-20 in my case).
I would like to provide more information, such as logs, but I'm not sure where to find them.
distribution: archlinux (kernel 5.6.7-arch1-1)[other tested kernels: 5.6.5, 5.6.6 and 5.4.35(lts) don't work either] gdb version: 3.34.1-2 (afaik, the last update was in february?)