Tracks 7 and 8 not playing

I am playing a 8 tracks interleaved audiofile from the sound editor ,but only tracks 1 to 6 are playing, even if the audio output mapping seems correct and continuous (all software outputs are regularely mapped on physical outputs). The tracks 7 and 8 are not routed to the RME Fireface audio interface 7 and 8 but 10[Lsd] and 11[Rsd].

R.C.