Just been having a look through some technical documents for you and cant find an exact answer regards the fusing.
What i can tell you is that fuses (Fusebox C = lower dash) C3, C5, C12, C41, C47 control everything in your headlights (plus some other stuff like interior and rear lights) so one of these does the DRLs
Fuse 5 (interior and rear lights) & Fuse 12 (foglights) are the least likely but if it is only one lamp then my money is still on it not being a fuse
Out of interest have you changed to LEDs ? I have seen a couple T6s that had one DRL lamp base with the wires the wrong way around meaning an LED lamp would not work in one of the sides