In an attempt to try to find a work around I made the following change:
Settings > Desktop Effects > Advanced > Composting type > OpenGL > Qt graphics system > Native
(it was "Render").
I've now been running for nearly a week without seeing any freezes, it was at least one a day. As this is a KDE setting (I'm using Kubuntu) I guess it's not much help to the OP, sorry.
In an attempt to try to find a work around I made the following change:
Settings > Desktop Effects > Advanced > Composting type > OpenGL > Qt graphics system > Native
(it was "Render").
I've now been running for nearly a week without seeing any freezes, it was at least one a day. As this is a KDE setting (I'm using Kubuntu) I guess it's not much help to the OP, sorry.