How to resolve a problem with components with TO263 footprint (LM1086)
After transfering my schematic design to PCB editor,I got one additional connection that require conecting second pin (Vout) with Tab(heatsink) of TO263.
This component has internal connection between those two pins so I don't need to do that externally.
I think you have provided same pin number to both second pin and thermal pad that is why S/W is connecting it to both pads.
You can either change the pin number for thermal pad or can just route the the pins as it is no harm connecting them on PCB even if they are connecting internally in the Package itself.