Ok, Before and after the movement of the brush you can't place a portal on it. Yes it can hold a portal when it is not made to move. I set it to a func_door, and make a temperary trigger so it can go down. Is func_door to blame?

Also, what are the sound file names for it?

Func_doors are a bit funny with portals in my experience. Change it to a func_brush, then parent it to a seperate func_door.

I've had issues with something simiar to this before. I created a brush set at an angle (angled up 45 degrees), and after a trigger went off it would move the brush horizontal. For some reason I was never able to place any portals on the brush.

I finally figured out that it was being caused by the brush being at an angle. I set the brush to be horizontal in hammer and set it to start open (so that when the level loads it would be angled), and set the trigger to close the func_door the brush was attached to instead of opening it.

If your func_door is set at an angle in hammer, perhaps this is a similar issue.

Syon, I making come down. Straight down. If I do make brushes that have angles, I will remember that.

Also, what sounds do I use?