iPhone camera adds shadows under LED lighting

iPhone 15 pro iOs 18

I haven't seen a good answer to this problem. Here's what I've learned.

1. With the subject under strong LED lighting, camera software adds horizontal shadows in horizontal view or vertical shadows in vertical view. More below.
2. With "View Full HDR" turned off in Camera settings, the shadows are still there, but not so dark.
3. I cannot turn HDR completely off, apparently.

I have a desk lamp with a circular light and an incandescent bulb in the center. The old circle fluorescents have been replaced by LED circles. With both sources on, and with LED only, I get shadows. With 60W incandescent only, no shadows.

I replaced the center bulb with a 60W LED bulb. No shadows, BUT – with the light source moved closer to the subject, and with some reflection off the surface, the shadows return. So it seems the software mishandles LED lighting at higher levels.

I'll wait a day or so for responses here and then take this to Apple support. I just hate to jump through all those hoops to get to the right place.