Weird behaviour on booting after uninstalling Mate and Budgie Desktop

I have Ubuntu 20.04. I wanted to try different desktop environments so I installed Mate Desktop and Budgie Desktop through taskel following this link. I then decided to go back to the Gnome Desktop so I uninstalled Mate and Budgie with a list of commands, for example:

sudo dpkg --list | grep ubuntu-mate
sudo apt-get remove ubuntu-mate*
sudo apt-get purge ubuntu-mate*
sudo dpkg --list | grep libmate
sudo apt-get remove libmate*
sudo apt-get purge libmate*

Now I am experiencing several problems on booting. I recorded a video of the boot sequence where:

1. it shows a gray screen "mate-like"
2. it shows the ubuntu version in the left top area of the screen
3. it shows a very quick list of commands that suddently disappear
4. the login icon is different from the classic icon i saw before
5. sometimes the login doesn't show and it stuck with the purple screen until a hard reset or pressing ctrl+alt-canc combination. I noticed that it happens only with power supply plugged in

Maybe is something about the grub configuration but I don't know how to solve it. Any idea?

Thanks

1 Answer

This gray screen seems to be GRUB2 theme for Ubuntu MATE. Remove it with

sudo apt-get autopurge grub2-themes-ubuntu-mate

then reinstall whole Ubuntu desktop task by

sudo apt-get update
sudo apt-get install --reinstall ubuntu-desktop^

and reboot to check the changes.