Welcome to the Wyze User Community Forum @GreatRay! 
100% on point. I’m not sure what, if any, file verification protocols are in place on the cam after a download and before the application of the update. I would like to believe that the logic in the firmware would first do a thorough inspection and server verification of the downloaded package prior to an attempt to apply it. But, as long as I have been here on the forum, I haven’t read any posts that discuss that topic.
My experience, however, is that some updates fail. I have done bulk updates on many cams and the majority of the time they succeed. But occasionally, one or two fail. It is very rare for me though since I am running my cams on what I would consider a rock solid network for the cams.
Moreover, it supports my theory that it was a file download failure to the affected cams when multiple cams (16 V3 in my case), running identical firmware versions, undergo the exact same firmware update and it updates perfectly on the majority of the cams. To support this further, the cams will then successfully update by manual firmware download and flash to the exact firmware version that they were downloading during the OTA update process. This supports the theory that it isn’t the firmware but some random failure of either the download or install process.
One of my theories is that the bulk update process is part of the problem, blasting bits and bytes all over the 2.4GHz WiFi band to every cam at once. If the Router isn’t 100% on board and doing its expected duties, who knows what mayhem can be happening. Think US Postal Service during holiday rush. How many packages do they loose or destroy? Packet loss over wireless transfer is real.
With that in mind, and since Wyze can’t rely on the stability or effectiveness of all the cheap, poorly coded routers out there, I have requested that Wyze introduce logic that will complete Bulk Firmware updates progressively, one single cam at a time. Everybody in a nice, neat, que line being served one at a time rather than what appears to be the current shotgun blast approach.