Likely so, yes, from TuneIn, not Sonos. If they’re coming in to you through TuneIn’s process, TuneIn uses a ‘pre-roll” advertising package in order to pay for their efforts. It’s not quite the same thing as tuning a radio, unfortunately. 

Additionally, radio stations can bounce from aggregator to aggregator, so while this week, you get it via TuneIn, next week you might get it from iHeart Radio, or one of the other aggregators. 

For instance, I used to listen to baseball games on TuneIn, now I do have to use iHeart Radio’s plugin. The BBC used to have some of their network on TuneIn, but they released a plugin on Sonos of their own for UK users that carries most of the content right now. It’s kind of still a crap shoot, it seems. There’s never a guaranty. 

If you can find a URL for the station, you can enter it manually.