It could happen that a new kernel doesn’t work with your nvidia (geforce) grafical card. The problem could de the linux-modules, such as linux-modules-nvidia-460-5.8.0-53-generic.
You can check it by the following command
dpkg --list | egrep -i --color 'linux-image|linux-headers|linux-modules' | awk '{ print $2 }'To solve this, if you find that the last kernel does’t have a matchintg nvidia module, you have to install manually that module
sudo apt-get install linux-modules-nvidia-460-5.8.0-53-generic