dragonfly 4 problems at low speed

Hey guys I have a dragonfly 4 pro which shows alot of noise and jaggered ground at 5knots, as there seems to be alot of turbulance at that speed, when I start to get up on the plane it smooths out and is good but when I slow down to look at ground it seems to be just alot of colour and not very readable is this normal, I have the tranducer pointing down.