Getting clutter on Garmin Striker when depth goes below 20 to 25' and no jig showing up

I am trying to get used to my new Garmin Vivid striker 4cv. I am using it in a kayak with the transducer in a Scotty arm. Yesterday was my first trip with it and screen clutter would start to fill up the lower part of the display as I moved deeper than 20'. It was nice and clear and good fish arches from 15 to 20, but then all this clutter shows up as I go deeper. I have auto gain turned off.

I also can't see my jig/spoon showing up like I can using my old Lowrance Elite-4. If I increase the gain I start to get too much screen clutter that obscures whatever jig return I get. If I turn the gain down to try and dial out this deeper water screen clutter then I definitely can't see any jig return. I would expect to see the jig using either 77 or 200 khz when it is hanging  straight down.

Any suggestions? Close to returning it but hope it's something in the settings.