Instead of a Screen Shot, Use the image button to take a Screen Shot of the entire Piston, then hold the image and press save. This will add it to your pictures. This way we can see past just whats on your screen.
TCP-Cancel on Piston State Change is used in this case because you have a timer. Without the TC Policy, as soon as the motion is inactive, the Piston will Wait 60 seconds and then turn off the lights whether or not there is motion again. In other words, without the Cancel on Piston State Change, the timer has no way of restarting. With it on, as soon as motion starts again, the Wait period will cancel and restart once motion is Inactive again.
Weird, that one light will stay on…Take a SS as described above so I can see if there is something else going on that is causing a conflict.
You could also consider grouping the lights and only have 1 switch to deal with to control them all. This can be done via a Virtual Switch and a CoRE Piston. There is also a cool app called Trend Setter. It will group the lights and create the Virtual Switch for you! It will also turn the switch on/off even if only one light is on/off. I can control dim levels as well. Check it Out!