There are so many models in Harvey Norman with Washer Dryer combo.

Usually Washer Dryer Combo is front loading type. So you need front loading detergent only (low sud). The shop will not teach you all these. Thats why people claim combo got problem coz u put normal detergent, the machine sure kaput.

Anyways any washing machine regardless combo or not will kaput and not forever.

My Ariston combo, the dryer kaput first, now still using but the washer only (after 12 years - coz i only do laundry on weekend)