Lost one of my fences

I have 4 fence areas defined on my extended desktop (2 x 23" monitors) on Windows 10 Pro but I have lost one of the fences (had to swap one of the monitors and when I removed the monitor everything appeared on the other monitor but when I reconnected the second monitor back, only one fence appeared on the changed monitor). If I go into Fences settings I can see the missing fence listed but I can not get it to appear on screen. I have unselected quick hide (the three fences that are showing are set to Exclude the quick hide). It is not rolled up, I have double clicked all over both monitors, and have rebooted. I can see the files and program in windows explorer under the desktop which should be in the missing fence but nothing I do will make the missing fence reappear. This is Fence version 3.0.5.11, any suggestions please.