My system has developed an annoying sound problem, could be from the latest Beosound 5 update?

System is Beosound 5, Beolab 8000 and Beolab 3500 speakers. When the source is NRadio (BBC R2 generally) when a singer is holding a sustained note it is getting trimmed, the best way is a pinging effect?

It is as if it is getting cut every 0.5 second or so? It is  strange and hard to describe.

I have tried the buffering but no different.

Any thoughts?