Why is my iPhone 13 pro max saying my camera installation is incomplete

Welcome, franjell, to Apple Support Communities!

The most important part of that “Unknown Part ⚠️” message is that the system cannot recognize your Camera as a genuine Apple part.

The rest are a few reasons why this might be the case.

Have you had your iPhone 13 Pro Max serviced by anyone (even Apple) recently, or relatively recently?

Have you ever opened your iPhone?

What have you changed, on your iPhone recently, or relatively recently?

Hello,

Have you had your camera replaced or iPhone serviced in any way? If so that could easily be the cause.

iPhone parts and service history - Apple Support

"Parts and service history is shown only if your iPhone has had a part replaced or if a part isn't functioning as expected."

No matter the cause, your photos show you are still under a warranty so I recommend you contact Apple Support directly.

"Depending on your location, you can get your iPhone camera replaced—in or out of warranty—by visiting an Apple Store or Apple Authorized Service Provider, or by shipping your iPhone to an Apple Repair Center. Independent Repair Providers* also offer genuine parts by trained technicians for out-of-warranty camera replacements.

Get started with camera service."

I hope this helps.

That might happen if the camera somehow lost connection with the main board and has to be reset. If it's all original and hasn't been opened up, then I'd suggest taking it to Apple or an AASP for evaluation.