[Solved] A weird sound issue

When I fire up a vid to watch on my netbook there is often no sound. If I play an audio file the sound works correctly. If I then go back to the vid and play it again the sound works just fine. I have a desktop machine with the same setup and this is never a issue. Has anyone else come across this?

Software:

KDE neon

VLC (but the problem is the same with any vid player)

Qmmp

ETA: A recent update appears to have fixed this problem.