Martin, 

This is a community site, and while the forum moderators sometimes have time to respond to individual threads, their main job is moderation, and you’re asking a support kind of question. You may get a better response to your question if you were to call Sonos Support directly, rather than posting it here in this community. 

With the extremely limited information you’ve provided, I do wonder if this DR P4 radio station (?) has chosen to leave TuneIn, and is now associated with another streaming company. You might contact them directly, or check on that station’s website to confirm where their internet stream ‘lives’, it may be just as easy as installing a new radio station stream to your Sonos controller. 

As to the other concern about family members connecting, I’d need a bunch more detail to begin to hazard a guess as to what the issue may be. It’s rather evident, from the preponderance of posts in this community, that a significant number of people are able to connect in some way, so it’s hard to understand why your family members are not.