Now this is more info that's needed!
Ok, the bearings are forward. So you need to be careful WHERE you put the extra weight.
Let me guess, you've been putting the extra weight on the mirror box on its back - that is in the opposite direction from where the bearings have been moved to.
The best place to put the extra weight is more forward, best in front of the mirror box. Now I know this is not feasible because of the rocker box front panel too.
These are all problems many ATMers run into because of not enough planning or understanding of the mechanics at play. You need to think about where you are going to put the bearings along with their design, and plan the OTA around that. And you leave the rocker box design, especially its build, until after the OTA is finished so that you can work out the COG of the scope and only then can you design the rocker box to suit, and make weight distribution changes to the mirror box to suit again, ie more weight in mirror box means a lower COG.
I need to mention all of this not to put down or show mistakes, but to show the chain of errors that will help us all work out a solution.
The better solution is to look at putting the extra weight on th underside of the mirror box & again "forward" of the COG. This will stop the scope tipping down and falling up when at higher elevations. The COG has two dimensions - along the long axis and the short axis (ie towards the front and back of the mirror box). You've put the pivot point of the alt bearings too far forward so the scope us back heavy and why it tips up at high elevation.
Another thing that will help is changing the Teflon pads - make them smaller and space them as far as they can go. From your photo I see they are too close together. I also suspect they could be too large for the weight of the OTA. All of this means the action in altitude is too easy.
How did you come to working out the size of the Teflon pads and their spacing? This is important so we can solve the entire mechanical situation.
Hell of a lesson to learn about taking more time to study the dob design and plan one's scope a little more carefully
Alex.