How is NVIDIA Prime Render Offloading configured in Ubuntu 20.04?
Apparently the default graphics configuration in stock Ubuntu 20.04 does not properly support PRIME render offloading, but adding the "Proprietary GPU Drivers" ppa solves everything.
$ sudo add-apt-repository ppa:graphics-drivers/ppa
$ sudo apt update
$ sudo apt dist-upgrade
$ shutdown -r now
And everything works perfect on reboot.