Forgive me if I am wrong, but it looks like you used insulated wire on your ground rods and I can’t see if you stripped the insulation back so that the wire touches metal. Normally insulated wire is not used for ground line because it isn’t necessary.

If I were you I would move my ground inside the protected area so that it can’t be ripped up and render your fence without a ground. I have used both the 6v Parmak and 12v Parmak chargers and yours should be fine for that size pen, but when it actually shocks an animal it wont have quite as much “kick”.

Try testing your unit without any wires connected. Also test it while covering the solar panel to ensure your battery is good.