"Sticky" mouse click

I also concur @ouroumov that it could be a hardware fault.

I had the opposite problem a long while back where the mouse had random clicks… after cleaning the mouse buttons, it hasn’t happened since… just coincidence the system had updates. :wink:

Trackpads in my experience could act funny too if there’s dust, fingermarks or pressure on the surface making the hardware believe a finger is “tap and holding” a click, like here. Try giving the surface a good clean and check there isn’t pressure on one side of the touch pad.