Hi Chris,
It sounds like the sonar’s range is only 7m? In that case you’ll only be able to run terrain following missions at that altitude or less. Sorry, we don’t currently support blending sonar and map-based terrain following so it’s one or the other. So if a sonar is attached it’ll try and use that but then the missions need to be really low (under 7m because of the range of this sonar). If no sonar is attached (or you just disable it with RNGFND_TYPE = 0) then it’ll use the map-based terrain data and you can run much higher terrain following missions.