Optical sound output out of sync with video

[TTurbo23]

Hi there,

when using optical sound I've noticed the sound is not in sync with the video. I first noticed this running Virtua Fighter 3. I did ask on discord, but nobody has confirmed if it is working properly or not, so I thought its best to raise it here. Normal aux works fine and the optical output runs perfectly for everything using the same setup. Could this be treated as a potential issue please to be tested?

This emulator is excellent and i love your work.

Many Thanks.