Help with Depth reading

[pslbuddha]

I have a dragonfly pro 5, just over 1 month old. It has been updated with the latest updates. On one of my last outings, I lost gps tracking and the depth reading turned to vertical lines scrolling across the screen. I thought there was some interference from sand, so I cleaned out the mount location. Took the kayak back again and still had the same problem with depth reading. In the pic included, I was in 4 - 6 feet of water and stationary. Any suggestions on how to remedy this problem?