I’m surprised to hear that, because my understanding is that all the major broadcasters have a blanket licence to play all music (from major record labels). They can just stick a top 40 hit in the background of a soap without planning for it. Maybe that doesn’t apply to something as primary as the shows theme song.
I believe that’s exactly the problem - that licence is only good for the UK.
When shows are exported they’ll gut them. Top Gear is the best example I know of, on the netflix & bbc america versions, most the recognisable songs have been replaced by musak.