My failing memory tells me that some of the info that is "broadcast" is actually broadcast by only one station, for the benefit of all.
My satnav in a Golf stopped giving me traffic updates on request. Mr Google and friends told me to tune to Classic FM, leave it tuned in for a while, then turn off everything, and a few minutes later turn it all on again.
Next morning, traffic updates were working again.
I am no techie, so I do not know whether RDS and traffic warnings are associated!