@rwolder Welcome to the community and sorry to hear about your troubles. I am a community member as you and try to assist when I can. As you we have Cameras at my in-laws home and monitor them. I have not experienced the same issue, was lucky or maybe I do my updates differently.
With that said, when you tried to roll back the firmware on the cameras, did you name it correctly and put it in the root of the SD Card?
here is a link to explain how to flash the camera to a previous FW Version
Here is the location for the Firmware. Go to the v3 section, click on the Chevron (down arrow) to expand it. The version Numbers will be links to download that Firmware. It is critical to name the Bin file as it is described in the previous link.
In your case, it looks like 436.2.5 is the closest previous version you can roll back to.