UPDATE: I've been messing around with different things to try to fix this. Strangely enough, adding another board outline point fixed it. There is something going on with the particular point in the bottom left of the board.
I'm panelizing a PCB and there is some funkiness going on with the board outline on the duplicates. There is an edge of the board the disappears depending where the mouse bite goes. The radius'd lines of the tab don't quite meet the board either.
Disappearing line
Resulting Gerber preview
Line there, but tab radius funkiness.
Resulting Gerber Preview