Collide with object trigger - why animation only occurs on first encounter with trigger

when I play the lights are active at gameplay, then when the first time I collide with the trigger the animation occurs, then when I exit the trigger the lights turn off and the animation stops(which is what I wanted), but then when I collide a second time the lights still turn on but the animation stops. How do I get the animation to repeat? I have set up an animation controlled by the animator. The first step is idle then when I collide with 'Cylinder' animation occurs, then when I exit it stops as coded, but lights ony turn on in second collision but animation doesnt reoccur?