try mixing in either flaperons or spoilerons at different percentages. All my planes require one or the other to get a tight waterfall. flaperons mixed at 100% you can still fly out of maneuver without flipping the switch off (assume lots of expo is also being used). with spoilerons on exiting maneuver might get a bit tough to exit with a mix of 100% without flipping the switch off but 40-60% will work without flipping a switch.