2001 X5 E53 Check Park Lights

[Robo X5]

The drivers side (UK) park light is out.

The bulb that acts as the indicator and has two filaments in it. (Indicator and Park light), I am confused as the indicator still works fine via the same bulb.

I purchased a new bulb from BMW and fitted it but again the indicator will work but not the park light.

I then swapped the bulb holder and bulb from the passengers side over to the drivers side, but still the same issues. ie passenger side will work but the drivers will not.

I tested the voltage at the bulb holder on the drivers side and it is reading 12 volts.

Any help would be appreciated.

Thanks