I had this happen to me years ago with Lexar cards that were brand new with the first 5D (the one that didn’t shoot video). I contacted Lexar and they explained they need to update the firmware on the cards. Sent them back and never had the problem again.
The samples you sent look like drop out and because h.264 is GOP it is making up the missing info from other frames. Perhaps a call to Sandisk to see if they can look at the cards? Have you tried to blow air into the camera card bay to clean out any dust on the contacts in the camera? It could be the cards failing or the contact in the camera.
If this happens all the time, I’d get hold of a new CF card and see if the problem goes away. If it does, it could be your old cards. If it doesn’t it might be the cameras.
Also a rule of them, I use a Brother labeler and label each card. This way I know what card captured what footage. If I see an issue I can monitor the card. If there is no label they get mixed up and you don’t know what card could be problematic.
HTH.
Warren Eig
O 310-470-0905
email: info@babyboompictures.com
website: https://www.BabyBoomPictures.com
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