Trying to place wall lamps with Dynamo

Hello, I have this exercise for school : write a Dynamo script that places N wall lamps on a wall disposed on an ellipse of semi-axes a and b.

So first the script places N points following an ellipse shape. I then add the coordinates of the center of the wall to place it in the right spot. Finally, the “family types” and “family instance by coordinates” nodes put lamps at each points.

My problems are that only one point is placed eventhough I asked for more (8 on the screenshot) and the only lamps appearing is on the floor.
Does somebody know where are my problems coming from and how to solve them ?

My guess it is a lacing issue.