Most of the time when I do video with my Lumix DMC-G3, it works well and my Mac can read it. Maybe a few times I adjusted the settings on something else, so it didn't record a video as a MOV. Finally, my Mac can't recognize the memory card when I try to import the videos. My Mac can recognize all the photo files on the memory card, but the videos on the memory card won't show up from Mac Finder. I can see the videos on the memory card from my camera. How can make the video files show up in the card from my Mac?
You say you've changed the settings for the video files, they are not saved as MOV. That may be the cause why all the video files won't show up when connecting the memory card to your Mac but the photo files will.
Are your videos in the format AVCHD? This file format is workable on digital or HD cameras only but not on Mac machines. You need to convert the AVCHD file format into a format that is compatible with macOS like MOV or MP4.