Traffic reports stopped working - Stream MP3 PD170?

I have an 80 mile a day commute round, for the large part, the M25; a road well known for being a car park.

For this reason I leave the traffic reports (TP) on for most of the drive as to be notified to either take another way home or prepare for the long haul!

The other day I hit the back of traffic and realised that the radio hadn't chirped up once with the traffic reports. Since then I've come to the conclusion the function has entirely ceased to work?! I've tried many configurations of turning off and on the TP/ car and nothing seems to work?

Can anyone shed any light? Its a 58 P-FL PD170 vRS with a factory Stream MP3 and jumbo box.