Hey Zoltan,
I've been doing some further trials.
The machine that is lagging... I am able to select windows audio devices as outputs - however no sound will play.
When I play through direct sound (it works) I have to change the Sample rate to 48k and buffer to 512 and it will play in sync, however this isn't ideal as they're not default settings.
I've reinstalled sound drivers, tried a fresh install of resolume...
Not sure if there's a permissions issue here?
Next machine, which works perfectly fine with windows device analogue outputs.
If I use 'dante via' as the sound output (Assuming this is also the case with other dante ouputs, but haven't tested yet) Audio is in sync while I have no display output selected.
Soon as I output the composition to an external monitor I start to get bad delay issues.
This doesn't always happen straight away, sometimes the videos have to be played a couple of times before this happens. If I clear the clip and add it back the delay persists.
I've tried both DXV & mp4, same issues.
When I close Dante Via and switch device back to 'windows audio headphone' all is well again.
Let me know if you need anymore info that can help