I heard back from their support, they said the same thing. I uninstalled and reinstalled the whole thing (both AP200 and Benz Diag). Same result, nothing changed other than me having wasted half an hour. I also sent them a video and logs, so they should see exactly what is happening.
I don't have an Android device. While I'm happy that it is working on your Android, I bought this because it is advertised that it works on iOS, which is what I have. The fact that it runs on Android doesn't say anything about their iOS app, since they are two completely different platforms and apps. Apparently one of them works and the other one doesn't.
I don't know what you mean "the problem being with the iPhone". If you install an app on a perfectly working iPhone with the latest OS on which every other app runs just fine, then I'm pretty sure my iPhone isn't the cause of the problem.