Movement between extended desktops fails after video card upgrade

I have a 4 monitor configuration. 2 monitors per computer. I have been using synergy for many years. The top two monitos sit over the bottom two monitors. The top two monitors are driven by one computer and have the desktop extended across both monitors. The bottom two monitors are driven by another computer and have the desktop extended across both monitors. If I start in the top left monitor (on the server computer), I can move the mouse only to the top right monitor (the extended desktop) and down onto the bottom right monitor. I can move back up from the bottom right monitor to the top right monitor. I can move back and forth from the bottom right monitor to the bottom left monitor. I can move from the bottom left monitor up to the upper left monitor, but cannont move back down to the bottom left monitor without first moving over to the extended desktop upper right monitor and then down to the bottom right monitor and then over to the bottom left monitor.

This issue started after I upgraded my Catalyst driver for my monitors. I have attempted to move back to previous versions, but the problem persists. I have confirmed that the firewall is not an issue between the computers. For the life of me, I can't see why there would be a problem of an Windows extended desktop of two monitors being able to only connect with one of the Windows extended monitors of another computer.

Any suggestions?

Thank you in advance!