iPhone AirPlay volume goes silent when music tracks change

Can anyone please help, this issue started yesterday. When playing music on my iPhone and streaming via Airplay to any device the volume goes silent when the track changes. To get it working I have to skip back and then back forwards to the track, every time.

This happens on my Sonos, Soundslayer, and Denon Receiver. My Mac doesn't have this problem. Google'd around and tried the fixes suggested to no avail. Disabled transitions, rebooted phone, etc. etc. I think the iPhone installed an update overnight but I guess if it was that everyone would have the problem? Really don't want to reset the phone but I am getting to that point.

Any help gratefully received <3