Comment 26 for bug 1924823

Just to confirm everything I've written in message #25.
I've repeated the same tests with the deily iso 20/4.

The workaround at message #13 is no more needed for Ubuntu 21.04, but it can still be useful for Ubutnu 20.10

The step:
sudo apt install --reinstall grub-pc

can be more easily replaced by:
sudo update-grub