Neon switched to the xserver-xorg-video-intel-native-modesetting video driver. My system, Dell Lattitude E5500 (2010), doesn't react well on that. I tried to revert to the old xserver-xorg-video-intel driver but there is no way to do that. Muon shows the package in the list but it is impossible to install because it is a "virtual package". But when I do "apt download xserver-xorg-video-intel" this "virtual package" is downloaded to my home-folder and it doesn't look virtual to me at all! When I try to install this downloaded package the system won't do that too. I wish there was a way to simply revert to the old driver.
I think it should be possible to go back. Here https://packaging.neon.kde.org/neon/xserver-xorg-video-intel-native-modesetting.git/plain/debian/control I read: If you experience graphics problems installing xserver-xorg-video-intel will install the actual xorg driver for Intel GPUs and might improve results But to my regret that is NOT the way it works
I found a way to get in done! Just: sudo apt remove xserver-xorg-video-intel* sudo apt install xserver-xorg-core sudo apt install xserver-xorg-video-intel sudo apt autoremove sudo apt install sddm With every step unexpected thing happen. Wrong dependencies removed etc. But after the last step the xserver-xorg-video-intel driver is installed and all is well. I think the intension was that sudo apt install xserver-xorg-video-intel should do the trick. But it turns out to be more complicated/messy.
The modesetting driver is here to stay. If there are regressions or missing features compared to the intel driver, please report them to https://bugs.freedesktop.org/