I'm a little confused, so let me see if I am understanding this properly.
You import the photos into Lightroom automatically, and then later you can't import the photos a second time? Is that right?
If so, this is normal behavior, nothing is amiss as far as the operation of Lightroom is concerned.
I'm confused on why you want to import the photo a second time.
Sorry, no. That's the behaviour I was expecting and how I would want it to work.
The opposite is currently taking place:- the photo imports automatically - the same photo still shows up for import when manually importing from the device it was taken on.
It shouldn't show up as a photo that can be imported but it is until it's imported the second time (manually).
Oh, I get it now.
Sometimes cell-phones make smaller images for display on the camera screen, perhaps this is what is happening. If you examine the number of pixels (width and height) of the two apparent duplicates, are they the same?
Everything is exactly the same except the folder they reside in. File size, dimensions, name etc
So, the only thing I can tell you is that there are many different reports in this forum of Lightroom not finding duplicates properly. So many reports that I do believe there is some bug in Lightroom with regards to this issue. Whether or not this is your problem I don't know, but it sure seems like it. So, I would recommend you file a bug report, or comment on other bug reports on this issue, if such bug reports are present.
I realize that stating it might be a bug does not help your current workflow difficulties, but I don't have any other ideas.
Thank you, that does help - knowing that it's not my workflow at fault but is unexpected behaviour.
Thank you for your time.
Do you have the below Import module option for 'Don't Import Suspected Duplicates' checked? If so and duplicates are still being imported then try resetting your LR Preferences file. If corrupted anything can go wrong.