Triggers not getting detected properly

I have 2 triggers and a platform moving between them. the script is working for the most part except for one odd error. the platform wont detect the triggers unless it touches them from above. the platform moves up by default and when touching the trigger above it should go down however it just keeps going up. if i force it to go down and it touches the trigger it just passed it changes back to moving up as i told it to. anyone know why the triggers only get detected from below?

On the assumption that you are using Mesh Colliders for your triggers, you will have to make them Convex in the inspector for them to pick up collisions from the front and back.