At the Consol I have a Helix 12 chirp SI GPS G1 software version 1.150 . At the front I have a Helix 9 chirp mega DI GPS software version 1.540 it’s a G2N. The problem is my Deppe reading jumps around on the two units The units will say I’m in 74 feet of water when I’m in 2 to 3 feet actually . The helix 12 worked fine until I added the trolling motor mega transducer to the Helix 9. I know there was some discussion about turning something on and turning something off any help would be greatly appreciate it .