As a response:
The issue lays when you look at any kind of metal fence, pole, glass plate or stone pillar. Placed by the player or already part of the excisting world. It visually shows an extra part when approached. Don't matter if you have anything in your "quick bar" (or how it's called) or not. Added screenshots (see above) show the results for each material.
Bryan.
Added pictures.
No I have this problem no matter where I build it. My whole path in my amusement park was changing since this problem appeared.
It's already been fixed. You may close this issue as solved.