Washdown is Different from Siphonic in that Washdown pushes the waste out of the bowl unlike what you are used to where the toilet would pull the waste out.
The Low water level is normal because that is how much water the toilet was designed to hold in the bowl since it is a Washdown Toilet.
You toilet is not broken if it doesn't make the air bubbly sound because the water is being pushed out.
A Caroma ToiletOriginally Posted by Random caroma PDF
The Caroma is near the bottom of the chart here. Washdown Lg. Diam. Trap