RPi 3 B+ and HiFiBerry Digi+ Standard no Toslink/optical out

Hello,

I recently discovered volumio, and tried to get it to run with a RPi 3 B+ and a PiFi Digi+ v1.0. However, as I did not get any signal to the optical output/Toslink, I found this forum, and I thought to understand that this card was not really supported.

I then acquired the HiFiBerry Digi+ Standard… just to discover that I ran into the same problems. I do get sound on the 3.5mm jack of the RPi, but nothing on the Toslink. I tried the troubleshooting I found on this forum (selecting different HiFiBerry options and restarting multiple times), but with no success. The volumio volume setting is disabled, but I guess that’s normal as I do not use a DAC.

volumio version is: 2.587
HiFiBerry Digi+ HW 1.3
RPi 3 Model B+

Any help or advice would be truly great!
Claude