I refilled the tax interview - it triggered this time.
I also checked the calculations and saw that actually neither of the 2 calculations are correct - the actual payout should be $8.58 - I could figure out that the $8.64 was rounding down the decimals instead of just rounding them and that accounts for the discrepancy there - but the other calculation I differ from 1c to 4c on each total. If that's an internal calculation then that's okay, you'll score the 10c, but if that is being given to you by the payment provider, well then they're doing something funny.