Prius Gen 4 (XW50) - faults with dudu 7 after replacing old android head unit

Three things are not working

Reverse camera. When I put the car in reverse, the screen goes black for about a second, then returns to the dudu operation screen. I can't access the settings, the setting page loads but disappears.
I am not able to skip songs with the steering wheel control buttons. The volume works fine, so there must be configuration issue. I've remapped the buttons, but the mapping isn't working.
I'm not able to see vehicle data, such as open doors etc.

Can you please advise? The other Android unit was working fine. I just switched the connectors on the back.

Frodo stupid question, I guess, but what's a canbus?

I also have a Gen 4 Prius, everything works fine. What canbus are you using? I tried Raise and Hiworld and both of those work.

VishBK stupid question, I guess, but what's a canbus?

Nevermind the question, I see that it's some kind of adapter.

When I google it I find several on AliExpress for around $5.

Is there a particular one for Toyota, or will a generic do (assuming there is such a thing)?

Did yours come with the head unit, or did you have to buy it separately?

Frodo I had to buy it separately. Any Raise Toyota Prius one from AliExpress should do.

VishBK thanks, will do