There is a threaded wedge in the leg, the threads can get dirty or rusty and the wedge just spins with the leg instead of tightening. Sometimes you can tap on it(don't dent the leg) or slide it up and down while trying to tighten the leg and it might hit a spot where it catches. Other wise you might have to dismantle it and clean it. I have trekking poles, paint roller handles, camera tripod and a decoy retriever that adjust like that.