SD card reader

The dash cam is probably using a somewhat different format, whether intentional or due to a bug.

You’re going to get to sort out the low-level differences between the two file systems, and the two video formats.

Maybe initializing the card on a different device still works with the camera, and allows the contents to be transferred.

Check with the dash cam support folks, too.

Different devices have differing ideas of exactly what a FAT format might comprise, unfortunately.

Check for a firmware update for the crash, err, dash cam, too.