How to ground PCB to chassis using mounting hole with vias in Kicad?
Since you are not trying to solder to the pad, I would suggest that you modify the zone connection strategy in the footprint to be &quot;solid&quot; instead of &quot;thermal relief&quot;.
Right now, you only have 4 of the 8 vias connecting to the ground plane on the ground layer.  Setting the footprint to &quot;Solid&quot; zone connection will connect all 8.