MP4 videos not playing on MacBook Air or Iphone

I purchased a dash cam over the weekend and just tried to look at the videos on it. I've been on the phone with Apple Support for 2 hours and we can't figure out why only certain videos will play. When I input the Micro SD card into my MacBook it shows that I have videos and the size of the video - ranging from 34mb to 474kb and all are MP4 format. Some of the videos listed have a still shot next to them but others just have the Quicktime logo next to them. The ones with the Quicktime Logo are the ones that are not working - the others play fine. I have figured out that the ones that play are the ones when the vehicle isn't moving. The ones that won't play are when the vehicle is moving - which makes no sense to me. The same thing happens when I plug the Micro SD card into my Iphone 11 Pro Max - the list of videos comes up and the same ones will and won't play. I have reset my router, reset the computer and downloaded a third party video player onto my MacBook - none of it worked. On the list of videos - the first 12-15 play fine (vehicle wasn't moving - I was just playing around with it in the driveway). Then there are about 200 videos that won't play then there are 6 videos that will play. So its not like the SD Card was damaged at some point. Here's a screenshot of what I see when I try to play one on my phone and it won't play. The second one is a screenshot of what I get when I can play the video. Has this happened to anyone and can anyone give me some insight as to fixing it? Thanks for any input.