Photos and videos visible on phone., but impossible to import to a Mac

I have a Moto G 2nd gen, with android 6 (marshmallow). It appears that the phone contains some photos and videos which I can see through the Gallery, but I am unable to import to Photos.app on OSX. The camera app is setup to store images on SD. I have tried connecting the phone as a camera (PTP) and nothing shows up. I have also tried connecting the phone as a media device (MTP) and use the android transfer app, but the pictures do not show up in DCIM/ under "internal storage", and the "sd card" file list doesn't contain a DCIM/ directory at all. I have tried wiping the cache partition, ejecting and re-adding the sd card but nothing worked, I cannot find these files. Where are they, and how do I get them out of the phone?