If you select the "wrong" image in the Library Module, and then go to the Develop Module, does the "right" image appear in the Develop Module?
The images are consistent between the library and develop modules. Image 1 never gets imported, but I can view it ok with other software such as Win Photos or Photoshop.
Thanks for the thought.
Please show us a screen shot of the Import dialog window with the folder selected that holds the image, or images, you want to import and specifically the one image you say LR won't import and have that image selected, checked.
Then a screen shot of that folder in the library module and the Grid view in the main area.
And if you add both?
Other matters diverted me from this issue, but I wanted to come back and close the loop. Thanks to those who tried to help.
The issue is related to the fact that my VueScan scanner software assigns a sequential filename that fills in any missing numbers. That means that after I rename "file number #1" to "textname A" in LR, the scanner assigns #1 as the filename of the next file.
Somehow, LR seems to remember the former file name #1 despite the changed name and imports the former file. So I began changing the file names in the OS before they get to LR and then things worked fine.
That does not solve the problem, but I have no more time to work on it. It may have something to do with saving metadata, but a filename seems more basic. Life goes on.
Again, thanks to all who suggested ideas.