Usb hub was removed when I was trying to found SAS module.
After I put all back in the initial position, I noticed that is a socket where is not a connector from the harness.
For what is ?
Maybe for android auto capability?
I know from my previous 2018 Mazda CX-5, that the same usb hub does not have a empty connector.

I found a better picture with my bottom side of the usb hub

it means that is Android auto/ carplay capable?
The software version is 70.00.350 EU N

 

Your hub had android auto / carplay. ( the brown & black plugs confirm this )

I wouldn't worry about the empty socket.

 

indeed is correct. I have Android auto