The backup/rear view camera view does not work?

Hello, the AV unit in this vehicle is part of the touch screen display as well as the rear vehicle display unit. Have you had a chance to have a full system scan for any trouble codes done on the vehicle yet? This is something that a shop with a capable scan tool would have to do, AutoZone and other auto parts stores can only scan the engine computer as far as I know. I'll pull up some diagrams for you, I have seen this same issue come up before with the AV unit, which controls the radio on the touch screen as you know, but the AV unit communicates with the rear display unit on a network, so Ill check if there are any specific fuses for that as well.
Does your vehicle have a navigation system, and do you know if the Audio system is a Bose or just a base type of audio system? These vehicles come with different options for the Audio system and with or without a navigation system included. The wiring diagrams differ a bit with each option.

The problem is probably the coins in the CD player but here are the wiring diagrams for the rear-view camera so you can see the fuses that run the system. This guide may help as well:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the images (below). Please let us know how it goes

This is the Base audio setup with the AV Unit, Fuses 3 and 19 are in the driver side Fuse block, the Fuse 35 is part of a fusible link block in the engine compartment, these are difficult to see because they are encased in a plastic block which doesn't come out easily at all. You can try to look through the side to see if there are any burn type of marks, but since the radio and touch screen still work, I don't think this fusible link (35) would be burned. The coins will need to be taken out; they are definitely shorting out any number of switches inside the front unit. So even if you find a blown fuse, replacing it will not resolve the issue. You can see how many components are involved with this unit and this is only the base setup, the Audio setup with the Bose Amp is more complex.
It might be that the Eject Switch signal and Switch Ground are shorted together, but there are too many possibilities with the amount of sensors, something is affecting the communication to the rear module that controls the rear camera. So, you will need to have the coins removed first and see if the AV unit is still functional after that. It may be something a dealership has to do, if they need to install any new modules that need to be programmed first.