Do married segment restrictions apply (as I have perhaps mistakenly always thought) only to connections (<24h) or do they also affect stopovers (24h> ) ?

I'm building a DONE4 for next year. I want AKL-per-SYD. Looking on ITA at the two segments separtely, I see D availability on both. Putting them together, I get 'no flights found' -- even if I change to a multi-day stop at PER. Maybe a glitch in the ITA Matrix? (Any other free utility that allows specifying a fare bucket in a search?)

TIA