I have some wierd graphical issue

Solution 1:

Wayland

You may have a problem with an older computer, with an older GPU. Try this...

sudo -H gedit /etc/gdm3/custom.conf # edit this file

change:

#WaylandEnable=false

to:

WaylandEnable=false

Save the file and quit gedit. Then reboot.

/swapfile

Let's increase your /swapfile from 2G to 4G...

Note: Incorrect use of the rm and dd commands can cause data loss. Suggest copy/paste.

In the terminal...

sudo swapoff -a           # turn off swap
sudo rm -i /swapfile      # remove old /swapfile

sudo dd if=/dev/zero of=/swapfile bs=1M count=4096

sudo chmod 600 /swapfile  # set proper file protections
sudo mkswap /swapfile     # init /swapfile
sudo swapon /swapfile     # turn on swap
free -h                   # confirm 4G RAM and 4G swap

Edit /etc/fstab, using sudo -H gedit /etc/fstab or sudo pico /etc/fstab.

Confirm this /swapfile line in /etc/fstab... and confirm no other “swap” lines... use SPACES in this line... confirm NO TABS...

/swapfile  none  swap  sw  0  0

reboot                    # reboot and verify operation

Update #1:

GRUB

To make GRUB remember your last selected boot OS, edit /etc/default/grub and edit/add these lines...

GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true

then do sudo update-grub.