DAB Radio In Ford Fiesta Stops Occasionally?

It's like I can get a connection, but every so often it says Station not working. Is this usual for DAB radio?

Yes it is. You are in a poor or marginal reception area. The sound will not play if it is not complete. The data is sent with checks, and if it isn't correct, the stream will not play. Usually all stations are a problem, not just one station. DAB works through multiplexers, where all channels come through or none come through in most cases.

It could be one of the following:
Flat or marginally charged batteries or a loose power lead
Faulty radio
There's work or a fault at a nearby transmitter
Loss of preset list of stations after long period without use, or after a change of batteries
Interference

If the radio has an external aerial, ensure the connections are secure.
If the radio has a 'pull-out' aerial, ensure it is fully extended.
Set the radio to 'autotune' or 'scan' in case it has lost the station list after being without power for a long time. You may need to re-enter any preset stations.
Listen to an FM radio for audible interference, as this may give useful clues. If you can hear interference on the FM radio, and especially if the FM interference stops when your DAB reception returns, the two could be connected.

If you experience lost reception on only one multiplex, but are still getting others, there are a few possible reasons:
The signals have weakened to below the 'threshold' of reliable reception
There's work or a fault at a nearby transmitter
Unusual high pressure weather conditions are affecting reception
A nearby local or regional transmitter is swamping transmissions from more distant national network transmitters.

What to do?
If the radio is portable, try moving it around to see if reception returns.
If the radio has an external aerial, ensure the connections are secure.
Set the radio to 'autotune' or 'scan' in case the station has been lost from memory because of a weakened signal.