5 Indoor Amesia Haze - Powerstrains

The plants are growing, and all topped plants have succesfully developed 2 main shoots. Some weird things are happening though: One of the plants almost doesnt grow up at all, but stays really low as if it gets too much light ( would be weird cause i only use 450W and its 45cm away from the plant). Its leaves look really healthy though, deep dark green and huge. I'm just weirded out that it won't grow upwards. 2 plants also seem a bit weaker, leaves feel less stiff, theyre lighter green in color and the branches feel weaker. Anybody got an idea what would cause this? -> see pictures with descriptions My plans for the future are to let them grow up a bit more, before I bent them over and start the ScrOG