I just picked up a new Helix 7 G3 and I am definitely disappointed. Not trolling here but the fish hunter bobber I had was superior in recognizing bottoms and lures. I only get the odd blimp of my largest lures on max or near max settings. And lots of noise and bottom moving. I have software 1.83 and it sounds like that maybe the issue. I will try to update software and see what happens.
Just so you know, something is messed up with your set up because what you said about your bobber is NOT possible. In Situations like this I like to check the nut behind the wheel first…..
Did you turn on Ice mode? If no, this is likely your problem.
Do you have an Ice Chirp ducer? If no, then this is likely your problem.
Perhaps 1.83 could be your problem. I understand and 1.90 is now out and has had good reviews by ice users. You cannot go back to anything prior to 1.83 if that is what came on your 7 out of the box.
Good luck.