Apparently pre-rinsing confuses the dishwasher or something. Not doing it leaves me with residue all over the other dishes though 🤷
Just a note: Australia and NZ are 'officially' 230v but are in reality 240v.
We were historically 240v and nothing actually changed at an infrastructure level, just the standard which says we're at 230v -6%/+10% (which allows for up to 252v, ie. 240v +5%, the old standard)