I have had the same problem from time to time. There are several things that might help. I've taken such an atty to the sink, run warm water through it, and then blow the water out several times. Repeat. Repeat. That usually improves the draw. But if not, then I have soaked the atty in alchohol for 10 to 15 mins. Then draw some alchohol through, blow it out, etc., then let dry for a few hours (don't do this with isopropyl alchohol as it is poisonous. I used some cheap rum.) Then 3 drops of
eliquid directly on the bridge, and back to
vaping. That often clears the draw pretty well.