Graphic artifact

Unity Engine
1

Here is an image of a small portion of my game.
http://picpaste.com/bb_glitch.png-gLbQY9NU.png
The black dot is there. I have searched all through my app and have found nothing that it could be.
It only shows up in larger iphones: iphone 6S. Cannot reproduce on smaller iPhone or Android or Simulator.

It appears to be right in the middle of the entire screen, too. And it lasts between scenes!

Any ideas?

2

The item it’s on, is a texture that is scrolling.
But, because the black dot is in the very middle of the screen, that indicates something Canvas wide.

3

To me it looks like old data from a previous frame. Have you made sure that you have a camera in the scene which is clearing the depth and color buffers every frame?