On Ubuntu, after opening my docked laptop screen to use the camera, and changing the setting to connect the emulator camera to my webcam.
Now the emulator is unusable because interacting with it using the mouse becomes impossible due to it swiping on simple cursor movements (no clicking).
This means simply moving the cursor over the emulator now creates random and bizarre actions.
I've closed my laptop screen and reverted the webcam changes, but it has not fixed the issue.