Iron fence hitbox prevents gustball movement

I spent hours trying to tweak one of the putt putt golf course holes using the iron fence. The gustball would get mysteriously stuck at random places and not advance. I decided to see if it was the iron fence object itself and it was. I replaced it with a rough wooden fence in the same configuration and no more stuck gustball.

Here is the layout of how the iron gate fence (from add on store) was laid out when it has some kind of invisible protrusions that are interfering with ball movement. (corner pieces seem to be especially problematic as well as the long ones)