F28/Xfce update - lost monitor mirroring

[Robert Moskowitz]

Just applied an update.  It has been a few weeks since my last update, 
holidays and such.

I use Xfce.

I lost mirroring my laptop on the external monitor.  All I have is 
laptop or external or extend to the right.

I have had this times past, and fiddling around with the display dialog 
has been able to enable mirroring.  Not this time.

The resolution on both is set to 1024x768.  I have tried rebooting 
multiple times and have gone back to the old kernel.  But not joy in 
Mudville.

I will be working on building a new system with F30, but meanwhile, I 
want this system to work with mirroring.

Can anyone point me to something to try?

thanks