The 8.0.5 release contains the most up-to-date iOS audio implementation. Commits linked in this thread are also included in the 8.0.5 release.
To be sure, do you see the same issue in the DemoRunner when the DemoRunner is built from 8.0.5? Which devices and iOS versions exhibit the problem? Can you confirm that only iOS 18 is affected, or is the behaviour also incorrect on older iOS versions?
Are you certain that the device samplerate is being changed correctly in these cases? Some apps display a list of samplerates that might be valid, but selecting one of these samplerates isn’t guaranteed to apply that rate. Instead, iOS will attempt to apply the specified rate, but might end up applying a completely different rate.