Streambar with Virgin Media box - sound regularly briefly cuts out
I've recently purchased and installed a Streambar. My TV doesn't support HDMI ARC, so I've connected the Virgin Media box via the optical cable. The Streambar content has no problem but the VM box channel's sound regularly cuts out very briefly.
The VM box Audio options are Dolby Digital Dolby Digital to PCM
...but it happens on each I can't see anything else on either VM or Roku that obviously would resolve this. Any suggestions?