First I might say that this is not a firm suggestion but something to look over onsite to see how it might apply!
I wouold say that glues or adhesives of any type might not work due to the leverage the current mount has. Glues are strong but tend to be brittle. Something like a rock?
But if we hit a rock long enough and hard enough it eventually snaps!
I see the major problem being the way the TV is left hanging on the mount but a long way from the wall. That means each time you hit a bump, the TV is jerking down on the mount and has quite a lot of leverage. Somewhat like making the TV bounce much heavier/stronger or however we want to speak of it? Kind of like it has a crowbar to pull on the part mounted to the wall?
That makes any fastener in the thin wall, really doing a tough job!
Suggestions to look over. Any way to remount the TV, so it can be closer to the wall with less strain each time it bounces? That would be my first thought but are there things in the way to block view, etc. making that not practical?
A second thought would be to use a different fastener---if it has to be the same mount and same place.
One way to get more grip is to use something like mollies or toggles to attach to the wall. While a set of screws will pull out of the thin plywood, a fasterner that goes in and expands on the back to make a much larger support on the back of the wall will last much longer!
Are you familiar with mollies?
https://www.homedepot.com/p/Prime-Line-Molly-Bolt-1-1-4-in-Drive-50-pack-Z-10533/317693449
I would expect to them in less than a 50 pack! But they can be a bit of trick when dealing with foam under the plywood, if they are not something you've worked with.
Basic idea is that you drive them into the wall and first tighten the screw down a bit. As you turn the screw the bottom part where the yellow is will move forward and fold the sides out behind the wall. The trick is going to be getting the right length of mollie to match the thickness of the wall. Then there is likely to be a bit of trouble forcing the foam out of the way as it folds.
Once you have the mollies expanded behind the wall, back the screws all the way out and run them through the plated and back into the molly body!
One of the main hazards in this is not to tighten the screw too far and break the head off!
Remember when lots of offices had plywood walls over foamboard and the phones were screwed to the wall? I was one of THOSE guys and got lots of time screwing up peoples walls!
Interesting problems were an everyday affair. But on the good side, you always knew where your phone was going to be. It never slid down in the crack on the couch!
