DIAGNOSIS Grease is bypassing the slide-out grease tray and dripping into the base of the grill. This is a design flaw in the stock setup. The factory grease management system is inefficient.
FIX Perform a modified clean. Let the grill cool completely. Pull out the slide-out grease tray. Scrape it with a putty knife over a trash bag. For the welded-in channel beneath it, line it with heavy-duty aluminum foil before your next cook. Fold the foil up the sides to create a channel that directs all grease into the drain hole and cup. Replace the foil liner after 2-3 long cooks.
IF THAT DIDN'T WORK Upgrade to a third-party grease management system. Aftermarket solutions like LavaLock's Grease Tray Divider or a custom-fitted stainless steel baffle are available. These physically block grease from flowing into the hard-to-clean areas and direct it more effectively to the cup.
HEADS UP Never allow grease to pool in the bottom of the grill. It is a major fire hazard. If a grease fire occurs, turn the grill to OFF and close the lid to smother the flames. Do not use water. The resulting heat can warp the welded-in grease channel, making the problem worse.