Noise from hitch/towball when towing

Batleygrimmy

Just got back from our first trip to the South of France with our Sterling eccles Topaz, it has an Alko hitch and the last time I hitched up and towed it on our journey home the coupling was making a real squeeky noice at slow speeds it sounded like it was gripping the towball too tight, if that makes sense. any suggestions?.

I did lift the stabiliser and reapplied it, but it didnt make any difference, could it be the pads inside the hitch?