We are encountering the same issue with the AVCaptureSessionInterruptionReasonVideoDeviceNotAvailableWithMultipleForegroundAppserror. The user does not have Picture-in-Picture enabled, and no other app is occupying the camera. May I ask if you have resolved it?

FB17303841 (iOS 18 System Bug Causes URL Scheme Failure)

The root cause has been identified—it's not a VPN issue, but rather a problem with iOS 18's Face ID unlock + app hiding feature. Reproduction steps: First, add your app to Face ID unlock and hide it, then uninstall the app. If you reinstall the app afterward, all CFBundleURLTypes configurations will fail to work