This may not be your issue, but after a few years of use, I have had different model cameras report that there was no SD card, and I cannot view the playback, saying “no video at the specified time”, but I have confirmed that it thinks there is a card present, and the camera says there is space occupied on the card.
In all cases, when I have taken the card out and looked at it, the video recordings have stopped at some point. Looking further at the card and its contents, I have found in each case, that the card reports that it is write locked, and cannot be written to or deleted from or formatted.
So the problem is, that the cards have ‘worn out”, and can no longer be written to, so the camera reports no card available.
These have all been “regular” cards, not high endurance cards. I have since switched to the high endurance variety cards, and it has been several years now, and I have not have it happen since then.