Import vom iPhone fehlerhaft (Porträt, Kino, ...)

Also see:

HEIC and HEVC media files support in Lightroom and Camera Raw | Adobe

and:

Using HEIF or HEVC media on Apple devices | Apple

Some questions

1. What particular iPhone?
2. What particular version of LrC?
3. How are you importing (Physically) by a USB cable from iPhone to computer?
4. How are you importing (Logically) within LrC in the import screen and selecting Copy, or Copy as DNG? or first outside of LrC by copying the images to a hard drive, then inside LrC import via Add?
5. As the iPhone apparently saves the "special mode" images with the file extension .hic instead of .heic, have you tried renaming the images involved on your hard drive as so to change that file extension to .heic?

A note.

In some non iPhone cameras, Sony and Fujifilm for example, the heic file type has been added as an option for jpeg. These cameras save these images as .hic (or similar). If the user copies the photos from the camera to the computer via USB cable between camera and computer, these files may get renamed so that on the computer they are named with heic as the file extension. If the images are copy's via a SD card reader to the computer, they do not get renamed (mind you, LrC still does not support them, Adobe has not gotten around to supporting heic from anything other than iPhone)