Mounting knobs

[steve1206]

I know this sounds like amateur hour or like I’ve never owned a boat, but....I bought a 126sv for livescope to go with my 2 Humminbird Helix 10s...my first 4 months and 7 trips to the lake everything was fine and now the last 3 trips I have found a mounting knob on the front deck or on the floor of the boat when I got to the ramp (2 1/2 hour drive)..obviously I’ve tightened them well each time I’ve found this...am I missing something??

[fishin couillon]

Can't say I ever had knows come lose including my Lowrance units......are the teeth on the bracket and unit seated correctly when you tighten them?