It started happening 2 days ago, with the new version of unity-system-compositor, namely silo https://bileto.ubuntu.com/#/ticket/2439 and https://code.launchpad.net/~unity-system-compositor-team/unity-system-compositor/0.9/+merge/316460
It started happening 2 days ago, with the new version of unity-system- compositor, namely silo https:/ /bileto. ubuntu. com/#/ticket/ 2439 and https:/ /code.launchpad .net/~unity- system- compositor- team/unity- system- compositor/ 0.9/+merge/ 316460