Chunky or separated wax can sometimes be fixed by super heating the wax by itself with the liquid removed. Follow the guide on how to remove the cap from your lamp. Pour the liquid into another container, but make sure to leave a small amount of fluid so the wax does not stick to the globe.
Put a small plate at the bottom of a pan to prevent the globe from cracking due to the extreme heat of the bottom of the pan. Fill the pan up with as much water as possible without boiling over. Bring the liquid to a full boil until all of the wax is melted. Let the lamp heat up for an additional 10 minutes. Let the lamp cool off completely then re-pour the fluid back into the lamp.