I have two identical Helix 7 Chirp Sonar/GPS units that I installed the new upgrade on a month ago. First time out yesterday one unit worked great, other unit shows solid colored bars in place of bottom contour lines in any sonar view. GPS and all digital read-outs including depth, temp, lat/long, appear normal. After resetting to factory settings and several re-starts, I got a week bottom contour but eventually went back to solid bars. Anybody else experienced this? Thanks