Eric,
No expert here on CRG brakes, but the pads should have worn fairly evenly from top to bottom. It seems that the lower pistons in both calipers are not functioning correctly. Suggest that you take one apart for inspection. After you remove the caliper from the chassis, but before removing the brake line, slowly pump the pistons out about 3/8 of an inch. That will make it easier to get the pistons out later. Check for worn or hard seals, and for damage to the pistons and their cylander walls. Even if all looks well, new pistons and seals wouldn’t be a bad idea. And for sure, replace all of the brake fluid. If not comfortable doing this, have your kart shop make the repairs.
P.S. Replace the pads