Fluid noise under left door

[Quent]

Noise in 2019 Sierra Denali 1500 4x4 under or in drivers door or left fender.  Sounds as if fluids or water has ponded in door or nearby cavities.  Most noticeable at idle speeds into garage or stop start positions while braking.  Fluids sounds are as if fuel tank is slopping back and forth.  However to far from fuel tank to hear these sounds.  Dealer unable to replicate.  Anyone with similar sounds?

[Rocz3cqg]

Check the drain plugs at the bottom of the doors and remove them to see if any water drains from the doors.  Check underneath your carpet in the front and or rear to see if water exists. Pull the sill plate up to see if water is in the tracks. Water could be running down the A Pillar due to the Antenna or weather stripping malfunction.