LR Classic not importing some photos on first pass

This is my issue: When I import images from memory card into LR Classic, sometimes not all photos are imported. At end of import a message states that some images could not be imported and it lists them. I eject card and reinsert then begin a second import of the same card. It recognizes the already imported images as duplicates and then it does import the images it did not bring over on the first pass, or at least some of them. Sometimes it takes several passes to get all the images. 

Operating system and LR are up to date. Using Mac Studio but also recreated this using Macbook Pro.  I am an experienced LR user. 

I read the forums here and noted some similar import issues relevant to duplicates, file number resets, etc. None of this is applicable in my case. 

This does not happen on every import, only occasionally. Seems to be more prevalent with larger capacity cards, but as I say, it happens inconsistently, even with large cards. 

Not the end of the world, but if there is a solution I'm missing or if it's a known issue I would be happy to know about that. Thanks in advance.