HDMI Functionality With iOS 12 and Alpine Products
“With Apple’s release of iOS 12 for compatible iPhone models, HDMI input on compatible Alpine head units can no longer be used to mirror the iPhone video via the Apple Lightning Digital AV (HDMI) adapter. All HDMI-equipped head units are affected when used with iPhones running iOS12.
UPDATE: On October 30th, 2018 Apple released iOS 12.1. In our testing with iPhones updated to iOS 12.1 we have found that HDMI video playback on select apps function has been restored. However, screen mirroring function is not guaranteed.”