xfce screen detachment

[Russell L. Harris]

system:  amd64 desktop, debian 12, xfce, NEC MultiSync EA192M monitor
I don't know precisely how to describe the problem, other than
"detachment".  About every week or so, when using the rodent, the
entire screen -- borders and all -- moves with respect to the monitor
screen as I move the mouse.   

The only recovery method I have discovered is to reboot.

My hands and finders no longer are working well, so I likely clicked
on something or pressed a key to cause the problem.

RLH