Problem importing into "Photos" from pictures taken on a Windows device

I'm trying to do a bulk import of pictures taken on the Windows phone I used prior to getting an iPhone.

The "Photos" program on my MacBook Air (running Catalina) seems to "see" all the files, but will only import about 5% of the photos on the chip from the phone which is being read on an Apple brand chip reader. During the "Import" process, all the file names are displayed properly. They are all JPEGs with numerical IDs and a "WP_" prefix and either a ".jpg" or _Pro.jpg" suffix

All the pictures I've tested display normally in Preview.

Here's the really weird part: when I search for a specific photo (that Photos previously did not import) on the chip, Photos will display the file name in grey (not black) typeface (as if it is incompatible) but it will successfully import that single photo.

My first thought was that there was some incompatibility between the chip and my MacBook, so I tried the process on an older MacBook Pro (running High Sierra.) Same results. Next, I tried copying the pictures to the hard drive and then attempting a Photos import from the folder on the hand drive. Same results.

I thought a JPEG was a JPEG was a JPEG regardless of how in was created or where it was being read.

Any suggestions on what this partial incompatibility is all about?

Any suggested solutions?