2015 Tahoe LTZ - loose 3rd row?

[2015LTZ]

hello everyone. i have a 2015 Tahoe LTZ. i feel as though the 3rd row seats shake a lot when going over rough roads or bumps. any clue how to tighten them a bit? Same for the 2nd row but they're not as shaky as the 3rd.

i was thinking if i could add some rubber packing over the tightening bolts? also not sure which bolts to tighten...

 

[2015LTZ]

anyone?

 

[RST Dana]

Same issue with my 16. It seemed to be coming from the area near the rear pivot point. You could wiggle it up and down a tad. Tried to tie string between the seat and bracket to silence the noise.
Can’t hear now, but I traded it 5 years ago.