iOS not starting request, not sending issues (sentry-cordova)

My cordova-sentry implementation is not sending issues to our company’s on-premise Sentry implementation. I’ve allowed our domain in the config.xml. And everything is working fine on Android. By debugging I saw that the sentry code is reached, but I couldn’t really figure out the sentry-cordova.bundle.js code.

This is the code in my project I’m using for testing at the moment, which is called on deviceready:

    window.Sentry = cordova.require('sentry-cordova.Sentry');
      dsn: ''
    setTimeout(() => {
      console.log('capture message');
      try {
        throw new Error('test');
      } catch (e) {
        console.log('catch exception', e);
    }, 3000)

In the debugger area of Xcode(9.4.1) I do see the following extra output when I enable the sentry-cordova plugin:

 [BoringSSL] Function boringssl_session_errorlog: line 2871 [boringssl_session_read] SSL_ERROR_ZERO_RETURN(6): operation failed because the connection was cleanly shut down with a close_notify alert

Unfortunately, searching on Google for this hasn’t made me any wiser.

Any clue as to what the problem might be?

Using version 0.12.3, but also tried using 0.11.0 and 0.10.*