I haven't found a solution for it yet. Thing is that I like the s1, it performs well and helps a ton with my problem with eye domination. But the sight is really sensitive to positioning. Small movements along the rib due to recoil makes the sight picture (placement of the red dot) relative to my eye so that the sightline is off. My buddy has an older beretta 686 where the rib is flat underneath. It stays perfectly in place with no issues.
One solution is to drill a hole in the rib and screw in a tap/stop in front of the sight. But Im a little unsure if it will be enough or it the sight will tilt forward since the mount doesnt fixate properly.