(this is also directed at @Salah)
If you are on an nVidia GPU that worked with 22.04 but is blinking on 24.04 regardless of which compositor you are using: Tough luck, there is no known solution other than trying a different nVidia driver or switch nouveau.
If you are on an Intel GPU that worked with 22.04 but is blinking on 24.04 regardless of which compositor you are using try this:
sudo pluma /etc/default/grub
and change this
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
into this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_iommu=igfx_off"
save and afterwards issue this command
sudo update-grub
and reboot.