[psomers]

I have the same problem with my Mountaineer. The floor is probably 5/8" OSB. It can't be very thick. I put an 8' 2X6 turned up on edge between my floor and the two rectangular support bar under slide. I wedge it tight with door/window shims between 2X6 and bar.
When we have couple over to play cards at table I'm afraid we're going to fall through. If you think yours doesn't give, step between table and chair and watch table move.