Thank you for your answer. Audiophonics tell me that it s normal because raspberry is bitperfect and there is no mixer like in other drive to artificialy maintain pcm signal and lock...
Music plays properly. Before i never switch off my dac, now i just have to switch off the dac not to have the flashing message no coax input.
It s good for earth
Amazing sound with rune and this digipi+ anyway !