This is a DAB only (i.e. non DAB+) radio from about 2007 or so. With most UK radio stations switching to DAB+ (DAB Plus), this radio doesn't understand the newer transmissions and therefore cannot receive the vast majority of DAB stations (which are either DAB+ or are switching to DAB+ by the end of the month).
It's time to retire this thing. Give it a good sending off and instead get a DAB+ ready radio.