Fences service seems to be hanging while monitors are turned off

Windows 10 Pro x64 v1607.  I'm running a docked ThinkPad P50s laptop with 3 external monitors for a total of 4 active monitors.  I'm using DisplayFusion Pro 8.1.1 to manage wallpaper, screensaver, and taskbars.  Windows turns off the monitors after 25 minutes of inactivity and then requires login, the computer is set to not go to sleep if it is plugged in.

The problem does not happen every time the monitors power down, but this has happened several times since v3.0.3 was installed.  Never had a problem previously.

When I unlock the computer, none of my fences are visible and the normal Fences entry is not visible on the context menu when right-clicking on the desktop.  When I manually launch Fences from Start, I'm told "Fences does not appear to be loaded.  You may need to reinstall Fences."

I've downloaded and re-run the latest installer, but the problem still appears to be present.