I am running Ubuntu Mate as a guest under Windows 10.
After a while, typically as I work in other applications on the host (like composing this question) the mouse stops working.
It looks like a Guest issue, as if I disable mouse integration and use mouse capture instead, the mouse pointer does not appear.
And moving the mouse within the Ubuntu guest does nothing.
Right-Ctrl will un-capture the mouse and keyboard, so it doesn't look like a host issue.
Has anyone else encountered this ?