So, I’ve got a bunch of V2 cam/pans, all with sd cards in them. Most work fine, but some won’t show that there are any event recordings in the app – but when I look at the sd card on a PC, the event recordings are there and watchable. I tried reformatting the sd card, didn’t help. It’s been going on for a while now, many different versions of firmware (including the latest). I ran chkdsk on the pc to scan for issues – none. It’s the same when viewing with the app on any device (multiple iphone/ipads; various versions of the app, including newest). Any clues?
Are you set to continuous or event only recording to the uSD card? My opinion is set to continuous recording on all cameras.
Since you said you formatted the card, look at the card status in the app and note how much of the card capacity is used. Repeat in a few hours and see if that number has changed. That will tell you if stuff is being recorded to the uSD card.
Make sure an update did not change recording settings (has been known to happen).
Oh it’s recording all right – if I take the sd card out and look at it, I can see and view all the recordings. But in the app it says there aren’t any. (It’s set to event recording, and it is recording events correctly.) It’s just that the camera isn’t seeing the recordings even though they’re there. (I suspect it’s the camera and not the app since the app sees the recordings for my other cameras ok.)
It is actually a loss in bitrate data transfer between the Cam and the App thru the P2P connection established. On the older cams, you could see the bitrate drop to 0.0, they removed that from the newer cams. 
I suspect that it is a conflict between the App coding and the Firmware coding on the cam that Wyze needs to fix. I have seen many more reports of this recently and have experienced occasionally on some of my cams.
I have read some posts where users have switched to high speed read\write SD Cards to solve the issue.