The Wayland Configuration Glitch
Ubuntu uses Wayland as its default display server. When you connect your Ubuntu laptop to an external monitor or a projector, the operating system automatically detects the new hardware and attempts to select the “best” display resolution. However, occasionally, Ubuntu’s auto-configuration gets it wrong. It might detect a 4K TV but automatically force your laptop screen down to an unreadable 800×600 resolution to match an incorrect mirroring profile, or it might constantly flicker and change resolutions if the HDMI cable has a slight connection issue, aggressively trying to renegotiate the display handshake every few seconds.
Locking the Display Configuration
To stop Ubuntu from automatically changing your display resolution when plugging in monitors or during minor hardware hiccups, you must disable the GNOME display auto-configuration plugin.
You cannot change this via the standard settings GUI; you must use the dconf editor. Open your terminal (`Ctrl + Alt + T`). If you don’t have it installed, type sudo apt install dconf-editor and press Enter. Once installed, launch it by typing dconf-editor in the terminal. A graphical window will appear with a warning; click “I’ll be careful.” Navigate through the folder tree by clicking: org > gnome > mutter. In the Mutter directory, look for a key named experimental-features. If you are using Wayland, you need to ensure that the display configuration is strictly managed manually. Alternatively, a more direct route for X11/XWayland hybrid setups is to navigate to org > gnome > settings-daemon > plugins > xrandr. Find the toggle switch labeled active. Turn this switch to the Off position. Click the checkmark at the bottom to apply. By disabling the xrandr plugin, Ubuntu will stop trying to actively manage and automatically change your resolutions, allowing you to set them manually in the Display settings without interference.