SA tax code is taxing wrong in MYOB 2024.2

Hi,

I have an employee whom I'm paying a bonus to which puts their grossed up annual income in excess of $180,000, and therefore over the ACC levy for 2024-25 of $142,283.

I therefore taxed the additional payment as an extra payment and used tax code 'SA', I also ticked the 'Extra pay is exempt from ACC Earners Levy' box .

MYOB desktop payroll (version 2024.2) is taxing this payment at a flat rate of 39% when the 'Extra pay is exempt from ACC Earners Levy' box is ticked, and at a rate of 40.60% (39% PLUS 1.60% for ACC) when this box IS NOT ticked.

According to IRD tax tables, the 39% is INCLUSIVE of ACC levy. See extract from IRD below:

Can you please tell me why the software is taxing this payment like this? Is this a known issue with the 2024.2 release?

Cheers,