Cookies are not set by Javascript document.cookie (iOS)

Cookies sent by backend are stored, but not the ones set by app itself.
The following code:

```
document.cookie = "notified=1; path=/; expires=Tue, 19 Jan 2038 03:14:07 GMT";
console.log(document.cookie);
```

returns empty string ("").
Angularjs $cookies.put doesn't work either.

Also, in Safari web inspector, localhost cookies list stays empty.

Tested on iOS 12.4 device with cordova-plugin-ionic-webview v.5.0.0. No issue on Android.