Fiio M11 does not output spdif

Any idea why Fiio M11 (latest firmware 1.1.0) does not output to SPDIF when serve as a Roon remote ?
The M11 outputs SPDIF with no problem when playing music via Fiio music application or Tidal application.
Roon Core is running on Windows 10.
Roon version 1.7 build 571