Random Coal In Middle of Belt

[Verbesity]

I was trying to figure out why my copper production wasn't backed up with tons of copper stopping my furnaces from running and found out it was that a massive amount of copper was going down to supplement my secondary copper supply I'm using to make Science Pack 2s. I figured one of my drills had gone dry or something but when I got there it turned out it was a piece of coal in the middle of the track somehow not allowing the raw copper to go by. Sadly I didn't take a screenshot before I fixed it, but I have this one to show where it happened and why it shouldn't have. The setup should be putting all the coal on the top half of the belt.



The red circle is to indicate where the blockage was.

[kovarex]

Hmm, I have no idea how could it happen.
Did it happen again?
Do you have picture/save of it happening?

[Verbesity]

Sadly I do not. I Have no idea how it happened and it hasn't happened again since. If it does I'll make sure to get both.