Hi,
Maybe this issue is related to display issue with this topic but It occurs on Ubuntu Mate. On Ubuntu 20.04 the issue is not present.
On my humble HP 6910p there is second monitor attached. On the settings the notebook display is turn off and system push picture only on external monitor (primary and 1920*1080) . Everything is working fine except the situation during wake up after suspend. Then the screen on external display is teared/dizzy like this:
Picture on notebook is like that:
Workaround:
On Control Center -> Display I need to change resolution to lower one and then choose "Keep previous configuration". Then the screen is back to normal.
Graphic is ooold one but it works on Windows and Ubuntu 20.04 configuration.
Is there an way to UM push default screen configuration after wakeup from suspend?!