If you are using volume in the T8 I think DSD is not enabled at least that’s what I recall reading somewhere. Think I noted a similar issue hence needing the pre.
I’ll experiment with it when I can as my T8 is connected to a Holo Audio Cyan 2 via USB and I can try the volume on or off as I can put a preamp in the output chain. Currently I can’t physically access my setup due to some room and equipment limitations 