Lightroom Classic: Import misses multiple sequential images

When using the import screen in Lightroom Classic CC (Desktop Version) on my iMac several sequential JPEG files are often missed from the end. Most recently I shot some RAW files followed by 450 JPEG files (as part of a time-lapse) and after importing what I thought was everything directly from the card I noticed a discrepancy in the number of files. When I checked, the last 58 files were missing. They weren't showing in the import dialogue as a preview but I could access them through Finder.
I copied the entire contents of the SD card to my desktop and tried to re-import into Lightroom and this time it skipped about 20 images. An improvement, but still not all of them. Whatever I tried I could not get it to either display nor import the final few images. The images are in no way corrupted (I can open them in PS).

This has happened to me now 4 or 5 times. It has never happened with RAW files, only sequentially shot JPEGs.