New bellow keeps coming off

Recently I replaced the stern drive on my 1979 AMF Slickcraft 200SS. At the same time I replaced all of the bellows and gimbal bearing following the exact methods described in the manual. I cleaned the transom plate thoroughly, used a wire brush on the drill, ensured everything was clean and smooth, wiped down the surfaces with lacquer thinner and I used the bellows adhesive with the new bellows. I ensured that everything was secure and let it dry for a week. I also replaced the trim sender and gauge sender. All are Sierra parts. I put the boat in the water and heard water rushing in. We pulled it back out on the trailer and inspected it. The shift bellow was off at the transom. I pushed it back on and clamped it and used the boat for a couple of hours. It did not show signs of leaking until we were taking it out. The shift cable bellow came off again, I believe while we were pulling it out. The following week I tilted the drive up, flipped the lip inside out on the bellow and cleaned it with lacquer thinner until no adhesive was present. I sanded the adhesive from the transom plate and cleaned it several times with laquer thinner until I did not see any on the rag. After drying I reinstalled the shift cable bellow with fresh adhesive, tacky, and clamped it. It sat for a week. I inspected it after a week and it is off again. I have asked a number of techs why this happening and they are not sure, saying they have never heard of it. The other bellows have not been a problem. There is no bump or lip on the aluminum hub that the bellow clamps to like there is on the driveshaft bellow hub and the small drivenuts on the exhaust bellow hub. These provide a stop for the clamp when it is tight on the bellow. Also, when the drive is trimmed up the bellow does not appear to be overstretched when I put it on. It is folded up when the drive is down. Does anyone have an idea of what is wrong here? I really don't know what the problem is and I have followed the install instructions exactly. The boat is a 20 foot 1979 AMF Slickcraft with an 898 and the drive is an MC1, early alpha, with the tab on top.

When you put it on again, and the drive is extended up as high as it'll go,
Push the little clamp on the cable farther back so the boot doesn't look extended very much.

When the drive is raised, the boot shouldn't be fully extended and trying to stretch out enough to pull off with much force.
If you get it too far in on the cable, it should be able to push itself back out enough to not crush
the boot by driving it up into the case. Plus, ya normally don't use the outdrive in the full down position.

Run it full up and down, then back up, look in there to double check, but that should fix it.