Ok, I've got a ton of buttons
And I've set those orange lights AT THE RIGHT PLACE (two units above the base)

Right?

Most of them work.

As for three buttons... they somehow won't show up.

I noclip to see if they are there, and they are indeed making some light.

But not showing through the top of the button.
I've set the NODRAW the same for all buttons (the height, the bigger the height, the longer or the bigger the door moves)

So yeah.

Any suggestions?

Personnally, I also made my own button to see that kind of problems.
The problem is probably that the positionning of the button components is a little bad.

But once you made your button, you got the theory behind them, so you can then use prefabs quite easily.
With prefabs, you are sure that kind of effect will be good rendered, since prefabs are often taken from official maps and/or made with quality in mind.

This may be the best way to solve the problem without banging your head on the wall.