Rendezvous no reverse lights

The cars BCM in the centre console shows voltage at the reverse signal wire whenever the ignition is on and the parking lights are on. And the car still starts (if it thought it was in reverse it shouldn't start).

Still think its a fuse or missing ground.
So you have no idea what fuse or fuses are for backup lights?
Gonna get out tomorrow night and go through all fuse boxes, so any help would be great.

Turns out the system was back feeding because of a short.
At the plug for the rear hatch - the large black wire and two of the smaller black and brown wires had melted and were touching.
Cut out the plug, checked the wiring, lighting and motors in the hatch and everything was good.
Turns out the wiring goes through part of the frame, before entering the rubber protector going into the hatch. At this point pretty close to the connector, the wiring is not protected and may have shorted and caused some melting.
So I covered the metal and wiring with plastic loom and tape, and everything is working great. Attached a pic of the connector in question I cut out. Was fused together so you couldn't even separate the connectors.
Just an FYI for anybody looking, as there is like no info on this vehicle online.

Thanks you the tip though!