It's more likely that the station has removed its feed to TuneIn. (There are broadcasting rights issues to be considered when radio stations make their transmissions available outside their own areas, either directly online or through services such as TuneIn. So some stations tend to come and go from TuneIn's line-up).
To see if the station is still available through TuneIn, try to access it via your web browser, here:
https://tunein.com/
To seek out an alternative feed, go directly to the station's website or try Radio.net:
https://www.radio.net/city/dublin
(Once you've clicked on a particular station there, you'll find the 'Play' button at the top of the page)
To see if TuneIn is working on Alexa, simply try to access a diffeent station.