It depends, there are lots of different issues that can happen with SD cards and they all get lumped together. The issues you describe don’t sound like the larger issue with some Panv3s not recognizing the card at all. A failing card or even failing power supply would cause those symptoms. Also make sure you have the latest app and firmware on the camera, as there was a bug at one point that would say no video available, but then play it fine, which has been resolved in the latest versions. That was only when trying to load the event from the list of events. If you went to the SD card and just scrolled around on the timeline, it would always work. If your timeline has gaps in recording, I’d first try formatting the card in a PC with the utility I mentioned previously, and may also be worth trying a different power adapter.
It can be the camera going bad too, not saying that isn’t possible, but I wouldn’t jump to that conclusion yet.
I’ve had this same issue with multiple V3 cameras to the point I just figured the 1st on had gone bad so I replaced it. I put the old one in a spot I don’t need the SD card and randomly it would write to the SD card or not. The replacement work fine for months then stopped read/writing to the SD card. After a reboot it would work for a few hours again. A random number of hours. I replaced the SD card with a new one and it kept doing the same thing. It’s not in a place that’s easy for me to get too so I was just rebooting it a couple of times a day. After a few days now it has decided it wants to work again and has been recording for over a week without issue. It does live outside so maybe it just doesn’t like being cold.
2 days ago got a firmware notice for my bedroom V3 pan cam. Ran the update. Wife put in the sdcard that it originally was in it when this issue started. It’s been 2 days and running just fine (recording everything and letting me access it remotely) and the living room V3 pan cam was still screwing up (it would record everything but had to view it on PC would show video error using app). Got notice for the LR V3 this am (dunno why they were 2 days apart but whatever AND no I didn’t manually check cause wanted to test). Installed the update, still kept the original card in it and it’s been fine all day since updating the firmware. My phone updates app at night automatically so it COULD have updated the APP and everything started working before the firmware but at this point don’t care lol it’s all working right now again.