Ubuntu 19.10 is not supported. It reached end of life on July 17, 2020.
This is a bug/design feature of Xorg graphics drivers like Nvidia and AMD's. You can work around it either by explicitly configuring the driver to sync to the fastest monitor, or by enabling "TearFree" if available.
For a more long term permanent solution, using GNOME Wayland sessions should never hit such a problem. But that also requires your graphics driver support Wayland sessions :(
dreamcat4,
Ubuntu 19.10 is not supported. It reached end of life on July 17, 2020.
This is a bug/design feature of Xorg graphics drivers like Nvidia and AMD's. You can work around it either by explicitly configuring the driver to sync to the fastest monitor, or by enabling "TearFree" if available.
For a more long term permanent solution, using GNOME Wayland sessions should never hit such a problem. But that also requires your graphics driver support Wayland sessions :(