Komplete Audio 6 Mk1 SPDIF in no sound

Hi,

The SPDIF in is connected to a Roland VS-2480, which is set to Master clock for sync & runs in 24 bits @44.1 Khz, as are my Windows & Komplete Audio 6 Control Panel settings.
The connection is correctly IN SYNC.
Windows default is is set to SPDIF.

I can see input metering correctly visually within the Windows audio settings : sound is coming in correctly when the Roland is playing.

There is, however, no audio coming out of the Komplete Audio 6.
Outputs are set to Main everywhere, and work fine with Windows, Spotify, VLC, etc.
But no sound from the SPDIF input, neither on MAIN nor on headphones.

But, if i open Reaper (a DAW), arm 2 channels, it is showing SPDIF as the default input source for the channels and gives me sound immediately, without changing anything anywhere. In the exact same software AND hardware setup.

This is really leaving me stumped. Sound is definitely arriving in, but nothing coming out.

Any ideas?

Thanks !