Put a new 64Gb uSD Sandisk Extreme in V3 last week and has been recording fine.
The card was factory format FAT32.
Download FAT32format GUI (GUIFormat) - Seamlessly format FAT32
file system drives and partitions and avoid potential performance
issues in the future using this application.
(https://www.softpedia.com/get/System/Hard-Disk-Utils/FAT32format-GUI.shtml)
God bless you!!
I have the same issue. If the power is cut to the camera, I have get on a ladder and pull the card and reinsert it. After the card is reinserted there is content on the card but not after the power cut. Also notifications for the camera stop when power cut and resume after the card is reinserted.
Does Wyze have a fix for this or do I start test formatting with the new card that I got from Wyze? I assume that Wyze formatted their card correctly before sending it to me.
Hi @dsvaleri not sure what “same issue” is. There is no quote or ref. to whom you are referring.
Two of my Wyze SD card have the same problem, Cards are not recognized by V3 after power interruption. Other brand cards work fine. Too late to return ;(
Hi @Andrei I would go ahead and give Wyze Support a call, worth a try.
If the troubled cards get a full format that whould bring them back
to new function albit smaller capacity. (V3 sd card not recognized after power off or reboot - #4 by dr.know)
You can also Vote that Wyze will get endurance cards for sale here.
Thank you, Doctor! 
I’ll call them tomorrow.
I had this same problem with 2 V3 cams and 2 Wyze-branded Micro SD cards. The Wyze cards work fine if you install them while the cam is powered on. But as soon as the power is cut, the card is no longer recognized. I tried re-formatting the cards with my computer to the FAT32. I also did a secure erase to re-write every data cell on the card. Nothing worked. Installed SanDisk cards and those work just fine, no problem at all. It appears the problem is specific to Wyze-branded SD cards. After spending hours on this problem and having to hang out a 2nd story window numerous times, I certainly don’t intend to buy the SD cards from Wyze in the future. The cameras are great – love them (I now have 5 of various models). Will ask Wyze for a refund for the cards.
I called them today. They didn’t refund me because it’s not reported (or known, or registered, I don’t remember the exact word they used) problem with SD card. So, they sent me two new replacement cards instead.
To follow up on my original post, I contacted Wyze support via email and explained the details of my problem. They agreed to let me return the Micro SD cards for a refund, issued an RMA and sent me a prepaid mailing label which I used yesterday to return the cards. I was a little beyond the 30-day period for the cards, because the cards had been shipped several weeks before the cameras, even though I had ordered them at the same time. But they honored my return request anyway. The SanDisk cards are continuing to work fine in the cameras.
Thaks for the good news @ralphmarston That was good of Wyze. Wish the cards were better quality. (Wyze 32GB uSD High Endurance)
I have the same problem with SanDisk cards. As soon as the V3 loses power - the SD card is not longer readable. ANY card you insert into the specific V3 camera will not be recognized until you re-initialize the camera.
The card has to be reformatted as well, I stick it in a V2 camera and it works there, so I use the v2 to reformat the card - then I reinsert it into the V3 and its all good - until the next time I lose power.
Thanks, joedel263 The download of the FAT32format worked on mine as well.