Swimming pool van sweeper?

we have a van pool sweeper that worked great for many years. recently, the suction hose continually twists up, prevent full area sweeping. I have checked the hose section couplings and all are tight, including the one to the head of the unit. pump suction appears to be normal and it does sweep up dirt and worms etc, but the hose is always twisting up. appreciate anyones thoughts. thanks