Excess private health reduction estimate incorrect

We've had a NOA come back with excess private health reduction correctly calculated at Tier 2 level.

This was different from the MYOB tax estimate provided to our client, which calculated at Tier 1.

Possibly MYOB didn't include $30,000 of reportable fringe benefits in income for surcharge purposes, but then the income would have been right back at 'base level', so this doesn't really explain the difference.

No Medicare levy surcharge was payable, so this doesn't seem to be covered by the 'known issue', for which there is a Hotfix - or is it? Can anyone help please?

Thank you.