I searched some dates in late June for 4 people in Liverpool. I narrowed the parameters to entire houses with at least 3 bedrooms.
The vast majority of places are significantly cheaper than yours. What Airbnb wants is to book the most number of places possible. When someone searches, the cheaper places tend to go to front of the search listings. I guess they have determined that when people see a whole bunch of listings with cheaper prices, they are more likely to book.
I suspect this why you are not showing up in the front of the search listings. When I did another search for the Orwell Park area, I did see your houses.
Do you update your calendars frequently? That’s an easy way to boost your ranking. Some people also say that updating your photos helps.