Window not cutting curved wall

[mpicciniJQCU4]

I have an issue with a window family I have downloaded from the NBS and then modified it. It does not cut part of the curved wall it is hosted in.

I have added a void form but this not solved the issue.

Is there anyone able to help me here? 
Please see attached the window family. 

Thanks, 

Marco

@dzanta 

[vitorbortoncello]

your wall is attached to another element, such as a floor or roof. Try detaching it

[mpicciniJQCU4]

Thanks for your reply, 
The wall is not attached to anything.

it must be an error with the family. 
See below how it interacts with a more curved wall:

Thanks, 

Marco

[mpicciniJQCU4]

Thanks for your reply, 
The wall is not attached to anything.

it must be an error with the family. 
See below how it interacts with a more curved wall:

Thanks, 
Marco

[Simon_Weel]

Extend the Void outwards - it's too small right now.

Original:

Modified: