you may actually have hit the point where you have too much FOC for that set-up.
That I highly doubt, The higher the FOC the better arrow flight and penetration, I have tested arrows up to 34% FOC out of my long bow and compounds and have yet to find the point where I have too much FOC.
Actually SC, she's a good bit overspined, and the only fix might be more tip weight, but then her FOC is gonna go from 15% to 18%, which may just worsen the problem.
No going to 18% will help some, but untill it gets to over 19% most people are not going to see any difference and those differences are a huge benefit to flight and penetration.