if the glue has come unstuck take the whole end off place the small bit that goes over lower section in a vice then unscrew it once undone glue bottom section back onto pole.
to stop these sticking the sections have to be kept really clean bits of grit mud etc get lodged in the clamp and this means you tend to ver tighten them to stop the pole sliding and then they get stuck it happens to mine regular and is a real pain, i wish they would make them ith clamps similar to ones on wfp as then this problem wouldnt happen.