Echo Dot and TuneIn as a wakeup alarm. Stops playing after advert.

[Nutter]

We had been using the Wake up to music Alarm function on an Echo Dot for a while. Recently over the past couple of weeks the alarm triggers at the correct time and plays the intro TuneIn advert then .... silence. If I look in the app I can see at the bottom of the screen the "equalizer" bars moving as if its playing something but the Echo Dot remains silent. If I ask for the radio station to be played it works without issue. Anyone have a solution to this?

Thanks.