I had replaced my Lowrance X97 with a Lowrance LMS-522ciGPS and was having a problem with the sonar returns falling out whenever I operated the trolling motor. The graph stopped showing most sonar returns in the water column just like the sensitivity had been really turned down.

The trolling motor was a Minkota Maxum 74 with a universal sonar puck and I didn't have that problem while using the X97 graph.

I almost posted on here asking for suggestions as to how to correct this problem but discovered what was causing the problem. On the sonar adjustment menu the first line was for sensitivity adjustment ,which we are all familiar with, and on the second line was for Auto sensitivity being on or off. When I turned the auto sensitivity off the problem was corrected. I don't know why since that was to automatically adjust the sensitivety based on depth.

Anyhow just thought this info might help someone else.