java script will not run a second time

Hello, I have a project in adobe animate canvas with 4 frame when I click in the forward direction and go from frame to frame everything works. But when i click the back button the frame with the drag script stops working with elements (the iris button ) stop being drag able, i also notice that all the movie clips automatically play , I am at a total loss as I normally use actionscript , any help would be appreciated , I've attached the fla Im working on thanks