A sliding patio door that sticks, drags, or jumps the track is usually a quick fix. The problem is almost always in the track or the rollers at the bottom of the door.
Clean the track
Dirt, grit, and debris pack into the bottom track and stop the rollers gliding. Vacuum the track and scrub it clean, then wipe it dry. A dry lubricant (not oil, which attracts grit) on the track helps it slide smoothly.
Adjust the rollers
Most sliding doors have adjustment screws at the bottom edge, often hidden under small caps. Turning them raises or lowers the door on its rollers — adjust so the door sits level and glides without dragging or gapping at the top or bottom.
Replace worn rollers
If cleaning and adjusting don't fix it, the rollers are likely worn or seized. Lifting the door out (raise the rollers fully, tilt, and lift) lets you replace them. A bent track may need straightening or a track cap repair kit.