[monetzpond]

Valid message

 

[Bob Mariani]

The hole is normal. The tub drain is below the unit and can only be put together if this hole is there to work on it. Some tubs need support along the upper rim, some need a bed of plaster or motar but some need nothing.

 

[Ron6519]

I would have framed a wall behind the acrylic panels that went all around the tub. That installation is incorrect. There is currently no support if you sit on the edge.
The hole is normal for slab installations. You can cut a piece of cement board or hardie board to clean up the look if you want.
Ron