Lens profile shows “None” and the message “Unable to locate a matching profile automatically.” Setup is set to Default. Distortion and Vignetting are at the midpoint with value = 100
In Presets, Select +, Change Untitled Preset to “Import”. There are four entries under Lens Corrections:
Lens Profile Corrections—which is not checked
Chromatic Aberration—which is checked
Lens Distortion—which is checked
Lens Vignetting is not checked
(Seems to me Lens Profile Corrections should have been checked and Lens Distortion should not have been checked—but I did not change it.
Took a second photo to Develop and clicked on the “Import” preset. Remove Chromatic aberration was checked but Unable Profile Corrections was not checked. I checked it and got the same error as above. Under Lens Profile, “Make” I select “Apple” and LR fills in model and profile. Distortion is not greyed out but is set to 100. Setup changed by LR to read “Custom.”
Created a second present called “Import 2”. I got the same options as above, but changed them so the Lens Profile Corrections and Chromatic Aberration were both checked and the Lens Distortion and Vignetting were not checked. Also selected Process Version.
Went to Import screen and under “Apply During Import” selected Develop Settings as “Import 2”
Returning to Develop module, Remove Chromatic aberration and Enable Profile corrections are checked, Setup is Custom, Lens Profile was properly detected and distortion is not greyed out with 100 selected..
Imported 25 more photos from iPhone 7 Plus—all were properly identified.
From my existing library, selected 25 iPhone 7 Plus photos which were imported with no preset selected and in which the camera was not identified, went to Develop, and selected Remove Chromatic Aberration and Enable Profile Corrections. Lens profile was not found. Selected Apple and the Model and Profile were automatically selected.
So, I think my problem is solved, but there are two remaining issues for your consideration:
If one selects “Remove Chromatic Aberration” and “Enable Profile Corrections” and creates a preset, the top two of the four options should be checked, but 2 and 3 are checked instead.
For already imported iPhone 7 Plus photos, selecting Enable Profile Corrections fails.