The latest firmware made no change to the toslink optical output.
Please reboot everything, including Roon Core, Lumin and DAC.
If that still does not work, please use Lumin app to factory reset the Lumin hardware, under About of U1 MINI.
If that still does not work, please describe in more detail - does Roon appear to be playing? Does it make no sound? Or does it make audible noise? Please post a signal path screenshot.
I did everything you suggested
When roon starts playing a dsd file it tries to play it for a few seconds and then jumps to the next and it does the same thing again. No problem with pcm files
It doesn’t make any sound
I want to tell you that the lumin app plays dsd 64 files just fine but curiously enough since last firmware update it doesn’t downsample dsd128 files to dsd 64 but it does to pcm files with no problems
In Lumin app, you have to use the Custom Re-sampling function to convert DSD128 to 176.4kHz PCM or DSD64. Without this setting Lumin app will skip over DSD128 music files because they cannot be output to toslink without conversion.
In Roon, if you do not connect the U1 MINI USB output to a USB DAC, normally it should automatically convert DSD128 to PCM 176.4kHz. You may also set Roon DSP Engine to convert it to PCM 176.4kHz or DSD64 explicitly.
I’ll try to verify this tomorrow when I go to work.