Xcode runtime error for iOS iPhone 8 - [AXRuntimeCommon] AX Lookup problem - errorCode:1100 portName:'com.apple.iphone.axserver' PID:2751

I assume you have this solved by now, but for anyone else visiting, the error is informing you that the api used for AX Lookup is being denied access. If you are using Google Cloud Platform, this may be the case when you have a restricted API key. If this is the case for you,

Go to Google Cloud Platform Console, view your project, then go to APIs & Services -> Credentials -> click on the API key your iOS app is using, and under API Restrictions add the APIs necessary for your project. If you are using Google Firestore for storage, you should enable the Identity Toolkit API and Cloud Firestore API, in addition to any APIs you might use starting with "Firebase"

Hopefully this helped, and good luck!