SD card problems in all Sentry Plus cameras simultaneously

All three of my Sentry Plus solar-powered cameras developed SD-card problems at the same time.

Every day when I bring up the cameras, I get “SD card not detected”.

If I then go to “SD card management”, it suddenly finds the SD card. I have to do this for each camera.

By the next day I have to do that again.

When I try to play back video from the SD card, huge chunks of time are missing, and most of the time I get the message “No video available at the momento.” (Yes it says “… momento”.) This problem too recently developed on all of the Sentry Plus cameras simultaneously.

So for reviewing footage, these cameras have become worthless, though they worked reasonably well up until this problem developed. I’m not sure when the problem started, but maybe 7-10 days ago.

I’ve checked the firmware on all of the cameras, and they all say “Firmware is already up to date”.

What caused them all to stop functioning at the same time, and when will this problem be fixed?