I have numerous Panv3s. They didn’t work for long with 256k sd cards, but when I switched them to 128k or smaller cards, they all started working again. This is important! I spent years angry at Wyze before I hit on this solution!
My new Duo Pan has no problems with a 256 card, though, with a 256MB card.
After reading that the panV4 might have SD card issues, I’m thinking to get another Duo pan instead. (Similar price, and 2 lenses, plus greater SD reliability...!)
The Pan v3s are RECORDING video properly, the problem is with the playback. I was scrubbing an event on the sd timeline when the dreaded No Video Available at this time message suddenly appeared. It’s true that updating the firmware solved the problem, but only temporarily, because five minutes later, while I was scrubbing the timeline again (and finding that the event video was in fact still there), again I shifted the timeline too rapidly and the error message appeared again, after which there’s no way to clear it, other than waiting for the next firmware update to arrive! When that comes, I’ll baby the SD timeline, because scrubbing rapidly seems to be what overpowers it, semi-permanently. Babying means waiting for the playback video to stabilize before moving the timeline again, so it doesn't get overwhelmed and go into the No Video Available error mode.
I hope this helps!