Copy the images from the phone to a folder on your hard drive then import them into LR.
Is probably because the iPhone OS stores images in the Camera Roll which if it is anything like the Photos app on Mac computers places those images in some type of Package folder that can't be seen by any other program.
Not really sure as I don't have a Mac any more and never will again or an iPhone.
Thanks. But I never had this problem until last week.
Try unlocking your phone before plugging it into the computer. That worked for me!
I think PaulE911's answer is actually the correct one. I've seen this recently, and I easily reproduced the problem with my iPhone just now. I plugged in the iPhone and even though Lightroom Import screen lists the iPhone, it says No Photos and the grid is empty. But if all I do is unlock the phone, the Lightroom Import screen immediately starts displaying the photos.
This might only be a problem in Lightroom. Because Bridge, Photoshop, Apple Image Capture, and Apple Photos can import pictures directly from an iPhone without needing to unlock it.
It should not be necessary to manually copy the iPhone photos to any other location, so I don't think that is the correct answer.
I believe it is with more than just Lightroom, this is actually a OS (Windows)/iPhone issue. If you watch the Device drivers in the Windows Devices and printers, the iphone windows driver does not load unless the iPhone is unlocked when connected. Other programs may not use that driver as the link, so do not have the same impact, but this device driver problem is at the OS level and was not there in the past.
PaulE911's is the correct answer
I believe it is with more than just Lightroom, this is actually a OS (Windows)/iPhone issue.
But everything I described is on the Mac, so if it's the same problem, it isn't confined to the Windows OS.