That's light stress buddy. From the pic I can see your top cola is like 3 inches away if not closer. That is light stress, if u don't have enough room try doing what I did, but I don't know if your nodes will still bend with breaking the inside, you don't want to HST them, just do what I didn't in my monster&midget diary, just tie it down and you really could go any way as the 3 lights is a little overkill all facing on top. I'd move the 1s you on the sides
down on the ground and have them facing upwards at an angle focusing the light up through the bottom of your grow, this will ensure you don't have a top ready harvest while the bottom lags behind and it will with soo much light focused on the top and nothing for the middle. That's just me, as id want to get the most out the 3 lights and moving the 2 side 1s so they face upwards will give u a better overall yield and even bud quality/quantity tthroughout. Good luck pal.