I cannot boot using kernel 5.13.0-27-generic which was updated (automatically) yesterday. It causes the screen to flash some black and white stripe pattern after the ubuntu mate logo appears momentarily.
If I attach an HDMI cable and an external monitor, I can use the external monitor, but not my laptop display. Someone else has experienced a similar problem recently, see: Flickering snow on Laptop Screen in Ubuntu 20.04 with 470 drivers.
I am using the NVIDIA driver metapackage nvidia-driver-470 (proprietary, tested):
apt show --installed nvidia-driver* | grep "Version" Version: 470.86-0ubuntu0.20.04.2
And these are the two graphics chipsets in my laptop:
lspci | grep "VGA" 01:00.0 VGA compatible controller: NVIDIA Corporation TU106 [GeForce RTX 2060] (rev a1) 05:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Renoir (rev c5)
I can still boot my laptop but only using one of the older kernels that is still installed - currently:
uname -r 5.11.0-46-generic
The other versions of the nvidia proprietary driver that are available via Software & Updates (460, 495) fail in the same fashion.
For now I've set my laptop to boot using whatever kernel I last selected by changing grub as per: https://askubuntu.com/a/1308903