My daughter-in-law has a 2013 LR2. The brake lights are working but the 3rd brake light at the top of the liftgate is not. I changed the bulb (#921) but still no luck. Is there a fuse that will take out this light but not affect the normal brake lights?

Would appreciate some quick guidance. Inspection is due!

 

I'm not seeing any obvious clues in the book or online as to which fuse even feeds the 3rd brake light. I did check the voltage at the lamp socket and got nothing.