It turned out to be an issue with the Google Mobile Ads SDK. The version of the SDK we were using was still leveraging UIWebView. From the Firebase Console, we were able to determine that there seemed to be a correlation between when we started compiling our project with Xcode 11 (iOS 13 SDK) and how it affects the behavior of UIWebView. I found a StackOverflow thread that referenced a similar issue: https://stackoverflow.com/questions/58393257/crashlytics-thread-crashed-only-on-ios13-built-with-xcode11 UIWebview was officially deprecated in the Google Mobile Ads SDK as of version 7.55.0. If you're currently using that SDK, just update to the latest version. You won't need to add the plist entry as referenced in the SO thread. We noticed that the issue went away in Firebase after updating. Hope this helps!