iPhone 12 Pro Max unusual lens flare, glare, ghosting issue!

There is nothing unusual in your photos and as LD150 correctly assesses, you are taking night mode photos directly pointing the camera at bright light sources, which would absolutely do what you posted. Avoid taking night mode photos directly of bright lights. Also look at your iPhone screen and you'll see the flares plainly. Had you angled the phones camera differently, you could have avoided or greatly diminished the flares.

Bottom line is there is nothing wrong with your camera.

To illustrate my point of angling the camera differently, please see the following two photos I took with my then iPhone 12 Pro Max of Holiday lights on my deck. I never moved my position. I saw the flares and repositioned the camera to eliminate them:

Night mode uses time exposure of anything up to 3 seconds and strong point light sources should be avoided.

Its only in the last few years that this kind of shot could be taken at all.