It is on X and R, but not on the Z - the switch assembly is the banjo bolt.

Quickest way to get a ball park idea of what's wrong is to unplug the connector to the brake light switch and use a multimeter to check continuity on the switch side (and switch function) with brake on/off.

Test the tail lamp by applying 12v to the green/yellow wire on the lamp side of the connector to test stop light LEDs. (Brown is +12v supply to switch and green yellow is feed from switch to stop lamp)

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