I would just like to clarify how you're solving repeatedly, because the solver should not return a worse (in terms of quality) result than that provided in the initial guess if a valid solution is supplied.

The correct way to go about repeat solving is to click the solver button and let the solver do its business. If the solution is an improvement over the initial guess, click the "use solver result" button to replace the initial guess, then click the solve button again. Rinse and repeat.

Is this what you mean by repeated solving, or did you just hit the solve button repeatedly and sometimes the result returned was worse than a prior result?

I've also run into multiple instances of a solution with a strange action tacked onto the end.
This is a known "feature" of GA. Essentially, if there is no change to the quality of the result, the algorithm can't tell if the solution is better or worse than another slightly different solution so it leaves in some actions that have no effect on the overall outcome.