Hi John,
Many thanks for sharing the files! Without disclosing the detail here, I can comment on the issue as the following.
I took a quick look at the assembly. I think I know where the problem is. Though the behavior looks wrong in terms of the assembly design intent, it is actually a legitimate solution from Assembly Constraint Solver’s perspective. The rocker subassembly has way too many degrees of freedom. A limit angular constraint can help restrict the movement. Just open the rocker subassembly, add the angular constraint between the rocker arm and the bolt, and set a reasonable limit range. It should work better.
Thanks again!