Ndac and iPad m1 pro

My ndac is recognizing my iPhone but not thé News iPad m1 pro. Are there some suggestions ?

Are you using Apple Music on the iPad? This should work with the NDAC USB input as this had official Apple ‘Made for iPad’ certification when it was released. As far as I’m aware this continued to work with other iOS devices (iPhone, iPad) too, but whether this is still the case with M1 models I wouldn’t know.

Apps other than Apple Music sometimes take a bit of persuasion to work via USB. If this is the case, playing something from Apple Music then going to your chosen app and starting play there usually works.

Yes I m using Apple Music and initially it worked then suddenly it stopped and I don’t know why

In that case I can’t see why it shouldn’t work.
Have you tried a restart (unplug power lead, wait a few minutes, plug back in)?
If that doesn’t work maybe try a factory reset.

Have you tried a different cable in case one gas a fault?

Already tried everything