RE.com and Domain search facility has been of limited use and unreliable over the years.
I recently did some experimenting on word search as I have not bothered trying for over a year - this is the current result:
Realestate.com.au searches for adds with each and every word included, ie if you search for: renovate; desperate; motivated; it will only display adds with all 3 words included. The same goes for paint brush or fire sale. Grouping "Fire sale" does not make any difference. Unless add has every word in it it will not select.
Domain.com is much more useful as it searches for any word ie: paint brush will bring up ads with paint or brush in them.
I generally use and prefer RE.com but as for searching regions as in Central Coast, Sunshine Coast or for search on specific words Domain is currently better.