I think the wind makes the plant swing from side to side, which makes the plant thinks that it needs to reduce this swinging. In order to do this, it has to strengthen the stem...This is what my theory is ...I can be wrong ....( I hope not)
I would keep a fan on at least low on the plants at all times during the light cycle, fans strenghen the plants stems and help with circulation.
it kinda needs that thick stalk right now tho cause its like prolly 3 inches tall with 2 lil leaves mine is a bit past that but i am going for being smaller and trying to get it to stop stretching i bend mine back and forth its like 2 weeks old now and is on 3 nodes as of today saw lil ones pop out yippii but ahh maybe try keeping it down cause its in a window like mine is but i am geting it out n the sun soon cause windows make the plants stretch kidna peace i guess i am just babling on