When I plug my iPhone into my MacBook Pro and go to upload, I see all the photos on the phone and when I hit the upload button, NOTHING comes through. I've waited over an hour and not one photo is uploaded. I've had this issue before with Lightroom on my old iMac, but it somehow worked itself out. Now on my new computer it is happening again. It seems to have no problem with my Fuji XT-2, but the iPhone will not upload. Any suggestions?
You may try and reset the Lightroom preferences back to defaults and check if there's any setting causing this issue, refer: Preference file and other file locations | Lightroom CC and 6
Also, you can move your images to the main machine from the iPhone and add the images from there in Lightroom.