I think FRO will follow the court order. In your case, that evidently has you paying a lot more, so you are going to have to get it changed.
Not paying June was a mistake, given your massive income drop. You want clean hands here, since you are likely at great risk of having income imputed to you. Take your current income, add 5% to hers, and then pay that amount.
Dear ex,
My income for child support purposes is X
Assuming you got a 5% raise, your income for child support purposes is Y
According to our agreement, we are paying offset support, so I owe you X-Y per month, when can we meet so I can give you the cheques (or... I have transferred the amount to your account, whatever you do)
You still have an obligation to provide me financial disclosure on a yearly basis, and if there is an overpayment of CS I intend to retrieve those funds with interest, and I intend to recover costs from you for the motion required to compel your disclosure.
5% is too high, but is not ridiculously high. It encourages her to provide disclosure, while not making you look like a complete ass.