optical & HDMI audio

I know dual audio threads had been discussed about 5 years ago and the conclusion was that you couldn’t get HDMI & analog audio to work. But I thought optical & HDMI did work.
I have a receiver with a second zone that only takes analog inputs so I have an optical to analog converter attached to my HTPC. This worked fine with Kodi 16.x but since moving to 17.x it has stopped.
Has something changed in the settings that I need to reenable or am I just out of luck?
If I am out of luck can anyone suggest an HDMI splitter that will pass through the digital via HDMI AND stereo via RCA connectors?
Thanks in advance.