Doesn't load config.xml if app is loaded from a subdirectory

After uploading an app to a subdirectory of a domain i.e. mydomain.com/store/ the app attempts to load the config.xml from the public root i.e. mydomain.com/config.xml instead of mydomain.com/store/config.xml

Note this is an Ionic 3/Angular 4 app, and built using the command "ionic cordova build browser --prod --release"

In my uploaded app, the offending line was here:
(line 875 in my file, function readConfig)

    try {
        xhr.open("get", "/config.xml", true);
        xhr.send();
    } catch(e) {
        fail('[Browser][cordova.js][readConfig] Could not XHR config.xml: ' + JSON.stringify(e));
    }

Same function on Github:
https://github.com/apache/cordova-browser/blob/f5df89f99302263fb149c6cec3f5168c0e3c4192/cordova-lib/cordova.js#L894
https://github.com/apache/cordova-browser/blob/dfa40a685780da5aff9965bd54aafec177113abc/cordova-js-src/confighelper.js#L69

I could list the URL to view the error here, but that app will change often, and it's easy to reproduce.