I use the excellent Sync Me app SyncMe Wireless - Android Apps on Google Play to backup my phone. It's nice because it doesn't require root privileges for most files I care about. One of the tasks I have configured backs up /sdcard/DCIM/Camera. On Lollipop, this worked fine. Since upgrading to Marshmallow, no new pictures are backed up. When I browsed to /sdcard/DCIM/Camera in the app, no recent pictures show up. When I browse there with My Files, I see the new pictures.