AD2428 A2B data stream

Hi everyone,

I'm currently working on setting up an audio stream in an A2B (AD2428) network with 17 downstream slots.
My problem is that it seems i can only get
up to 13 downstream channels when using 32 bit downstream slot size (reg 0x10) and
up to 25 downstream channels when using 16 bit downstream slot size.

It seems to me like this behavior is caused by lack of bandwidth,
I'm making sure all upstream slots are disabled but this doesn't seem to make any difference.

I know in theory i should have the bandwidth i need for my application so i would like to ask you any suggestion on what i could be doing wrong.
I attached dumps of both the slave and master registers along with screenshot of the TDM stream between audio source to AD2428 and AD2428 to audio sink.

Master dump:

Slave dump:

TDM audio: source to AD2428 master

TDM audio: AD2428 to sink

Thank you very much for your attention.

Marco Segato