I have just purchased a cheap-ish soundbar to improve the sound from my TV (Veon 55" 4K and a JVC 3.1.2CH)

The sound bar is displaying ARC but the sound only comes on for a fraction of a second then nothing for a few seconds then back on for a fraction, rinse and repeat.

If I switch to Bluetooth the sound is fine.

The specs for my TV say it has HDMI ARC.

I have set the TV to PCM.

I have tried all three HDMI connections on the TV, same result.

Any suggestions on how I could get it working correctly?

Thanks.