Another way to prevent sticking is to spray non stick spray on the grill BEFORE starting it. I usually turn it off right before I put stuff on it, spray it again and then reignite it. Otherwise the spray burns off while it preheats. Just remember NEVER to use non stick spray while it’s on. Very dangerous!
Also I like to turn one side off when doing something like this. That way if one piece cooks faster than the others, or you get any flares up from the juice you can always move the fruit over to the side that is off. Just a little tip for you.