Can't import from iPhone 12 mini to Photos in Mac Mini
I have a 3.6 GHz Quad-Core Intel Core i3 Mac mini with Sonoma 14.4.1 installed, and I'm using an Apple USB cable to connect my iPhone 12 mini with iOS 17.4.1 installed. The iPhone shows up in Photos, with about 15 photos/videos that are identified as New Items. I've tried "import all new items" and I've tried selecting one photo and "import selected". When I click either of those buttons, the Photos screen changes to "imports" but nothing actually happens... no importing.
I have restarted both the iPhone and the Mac, and tried again. No success. I have also tried Reseting "Location & Privacy". I clicked Trust Computer. Still no success.
The photo library for my computer is stored on an external solid state drive formatted in exFAT. This should not be a problem, because I was able to transfer photos just fine on April 6th, five days ago.
Similarly, I also cannot import photos from an SD card via a USB-C adapter, even though it shows up in Photos with New Items to import. And lastly, I have also connected my Nikon 35 mm to the Mac via a USB cable; as with the others, it shows up in Photos with New Items to import, but whether trying to select one, or import all, neither function works.
Any suggestions?
Mac mini, macOS 14.4