Prime 4+ Channel 1 Volume Problem

I have owned the prime 4 plus for a couple months. However today I have a problem with the prime 4+. I wanted to listen on my headphones but no sound came out that’s when I realised that only channel 1 had no volume I checked settings. But I found something when I turn on the cue button on channel 1 I can hear the track playing But when I turn it of no more sound. Please someone help