I haven’t ever seen Wyze make beta firmware available for flashing, but I think that’s a good question. What troubleshooting have you attempted with the problem Cams?
When I’ve had issues with an unresponsive Solar Cam Pan (and I can’t even tell from the app what the battery status is in that situation), I’ve unclipped the Cam from its mounting bracket, brought it indoors closer to the Wi-Fi source, and plugged it in to charge. While doing that, I hit the Cam’s SETUP button and reinitiate the in-app add device process, then when I get to the point where the Cam is back online I just swipe the app closed to abort the add process. That has reconnected devices for me without requiring a full reset or in-app setup.