YUP !!! Me Too!
With Sonoma 14.3 on my MacMini M2, my iphone 13P (with iiOS 17.3) all of a sudden Photos will not import photos. About a month ago (I was on iOS 17), when I did a series of imports, it stopped at some point (it seems about the time the phone went into sleep mode).
My normal practice is to have Photos App delete from the iPhone, those the photos that were imported imported; in these instances, while it did import some, those were not deleted. I spoke with Apple Care, and at that time it would not do that error (of course!). And the fellow there made it sound like he had never heard of this happening; "Photos is supposed to continue working even as the iPhone thinks about going into sleep mode". Cut to yesterday, I had 800 photos to import; not a one went. I tried with 230; nada.
It kept going into a loop, as another has stated, "Preparing to import..." , the cursor then jumps up to the top of the side-bar; nothing has happened. Reboot both - same thing.
Today to trouble-shoot I tried to import from my iPhone 8 (iOS 16.7.4); it worked fine!!
Come on, APPLE Corps!!
Now it has jumped to this annoying state. Anyone else run into this? Ideas? solutions?