Universal app and audio unit extension

cello,
Regarding Universal app
In GarageBand on iPhone the audio unit extension is recognised,
however on iPad the audio unit extension is not recognised.
Is there a box I need to tick?

Before this app was Universal it was set for just iPad and the Audio unit extension was recognised. I deleted the Audio unit extension, I intended on doing more with it later, and then changed the app to Universal and eventually re added audio unit extension.

beep beep!

Universal app and audio unit extension
 
 
Q