OK. DSD ( meaning DSD64 being the maximum that Scarlatti can process) is available as DoP via RCA SPDIF from Network Bridge and into Scarlatti DAC. It is also available using a single AES cable with the dual AES configuration deselected.To help isolate the cause of the issue can you connect this way? Is the same issue then present?
It may also be worthwhile reading this post from 2019 to see if there are any points raised in it that may be relevant to you: