Switch Linux Mint to KDE Plasma

Install Plasma:

sudo apt install kde-standard

During the installation, you will need to choose a display manager, as KDE Plasma uses SDDM. When prompted, select SDDM from the screen.

After installation is complete, you need to modify one of the options in the SDDM configuration file to prevent an empty on-screen keyboard from popping up during login.

Edit the file:

sudo nvim /etc/sddm.conf

Paste the following code:

[General]
InputMethod=

Save and exit.

Reboot the system

After completing these steps, upon reboot, the SDDM login screen will appear. From the dropdown menu, select Plasma-x11. At this point, Wayland is not yet enabled, so further configuration is required.

Check the KDE Plasma version:
To support Wayland, it must be greater than 5.20:

plasmashell --version

Install the required components:

sudo apt update
sudo apt install plasma-workspace-wayland

If SDDM is missing:
Install and enable it (it is generally configured during Plasma installation):

sudo apt install sddm
sudo dpkg-reconfigure sddm

Verify the Wayland session files:
Check if Wayland session files, like plasmawayland.desktop, exist in /usr/share/wayland-sessions/.

Switch to Wayland:
Restart SDDM:

sudo systemctl restart sddm

In the SDDM session menu, select Plasma Wayland to enter the desktop.

Verify if Wayland is running:

echo $XDG_SESSION_TYPE

Remove Cinnamon (Optional):
If you don't plan to return to the Cinnamon desktop, you can remove it:

sudo apt purge cinnamon