Hello tmat,
It looks like you've tried some great troubleshooting steps of your own. We can name a few, just to ensure nothing was missed.
We know you mentioned that you rebooted the cameras. If you have not already tried, reboot all the cameras and the iPhone to which they're connected. Often this simple step will refresh the apps and software on the device to solve numerous problems you may encounter.
It looks like your iOS software is up-to-date, but what about all the other apps on your iPhone? If you open the App Store and see an available app update, complete the update(s).
Since the issue happened after updating to iOS 16.3.1, it may be a matter of software compatibility. Oftentimes, the OEM (Original Equipment Manufacturer) will release firmware updates to help make sure the device stays compatible with the OS to which it is linked. Have you checked with Panasonic to see if there are any firmware updates available for the Panasonic Howmehawk Window Cameras? If not, please do so. If you're not familiar with how, you'll want to reach out to Panasonic directly for support with checking for firmware updates. Contact a third-party vendor - Apple Support. They'll be the best source of support for their hardware/product.
We hope this information helps you out.
Cheers!
