DIAGNOSIS: This is a classic sign of a foreign object caught in the leg mechanism. A screw, a paperclip, or even a cable tie can get wedged in the gears inside the telescoping leg.
FIX: 1) Lower the desk to its absolute lowest height. 2) Unplug it for safety. 3) Get a bright flashlight and inspect the entire length of the inner leg on the noisy side, especially near the bottom where it meets the floor foot. Look for any debris. 4) If you see something, carefully use needle-nose pliers to extract it. 5) Manually rotate the crossbar to retract the leg slightly to check a different section.
IF THAT DIDN'T WORK: The noise might be internal gear damage from a past obstruction. You'll need to contact Uplift. They'll likely send you a replacement leg assembly, which is easier to swap out than you might think.
HEADS UP: Regularly check the area around the desk legs and keep small items off the floor nearby. That grinding noise is the metal gears trying to chew through something they shouldn't.