The contact owns a 2021 Chevrolet Silverado 3500. The contact stated that while the vehicle was in park(P), the tailgate independently opened during rainy or inclement weather. No warning light was illuminated. Upon further inspection, the contact related the failure to NHTSA Campaign Number: 24V060000 (Latch/Locks/Linkages); however, the VIN was not included in the recall. The local dealer was not contacted. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 34,000.