I recently took photos and videos and am now unable to import photos over USB. Image Capture shows the iPhone without any photos, Photos says "No Photos". Image Capture was working fine until I went on a filming spree (48 photos and two 2-minute videos). I am also unable to move a video to the trash: the thumbnail disappears from the list, then the "Cancel" button freezes and has no effect, the video does not appear in the trash, and when I go back to "All photos" another video is selected. I can take new photos on the device but they are not saved to memory.
Unlike this thread, both devices are up to date: iOS 9.3.5 and macOS Mojave 10.14.5.
The same thing happened to a friend who had so many photos that the device complained of lack of space. My storage says 5 GB used and 7 GB available.
How can I transfer the photos and videos from the device?