My iPhone 11 has iOS 18.4 Beta and my new iPhone 16e isn’t supported for iOS 18.4 Beta (for now) and is on iOS 18.3.1 Beta. If anyone knows when it’ll be supported please let me know.
iPhone 16e unsupported for iOS 18.4 Beta
I'm facing a similar issue. My iPhone 14 is running iOS 18.4, while my iPhone 16E is stuck on iOS 18.3.1 and won’t update to the developer beta. As a result, I can't transfer data to the new iPhone since Apple prevents migrations from a device with a newer iOS to one with an older version—whether through iOS, macOS Finder, or iMazing. The irony is that the newer device is running an older OS.