G5 tower wiggle/deck flex

[sjd]

Hi all,

New member here looking for advice on a tower resonance issue. The boat is a 2021 25LSV with a G5 tower that displays significant side-to-side movement in any amount of chop. I can replicate this just by shaking it manually. What's most concerning is that the motion propagates into the gunwales, which visibly flex as the tower rocks. Even the seatback moves, and the flex causes a popping sound at the base of the windshield on the port side. The bolts throughout the tower are secure, and have been retorqued by the dealer - this has not addressed the issue.

Looking up under the gunwales it appears the tower base is bolted directly to the gunwale deck fiberglass without additional bracing or backplates. I'm guessing the fiberglass is thickened here, but I looked at another malibu with a G5 tower and it had two stacked backplates in this area - a long (appeared to be kevlar or carbon fiber) plate under a shorter aluminum plate.  The mounting bolts to the tower went through both of these.  

My questions:  

1. Has anyone with a late model Malibu observed this issue (and how did you resolve it - or is it common)?
2. For those up for checking - do the undersides of the gunwales on your boat look reinforced in some way where the tower base is mounted?  

Really appreciate your thoughts. Thank you.