Steps to reproduce the problem:
let date = new Date("2017-07-18T14:54:01");
let dateFormatterOptions = { day: 'numeric', month: 'long', year: 'numeric' };
let dateLocales = (lang === 'ar') ? 'ar-EG-u-nu-arab-ca-islamic' : 'en-GB';
let shortDate = new Intl.DateTimeFormat(dateLocales,
    dateFormatterOptions).format(date);

shortDate format is wrong in all versions of Chrome for Android.

What is the expected behavior?
I should get:
٢٤ شوال، ١٤٣٨ هـ
based on your stable desktop version and Firefox for Ubuntu 17.04. (I'm not sure about the 'dateLocales' for Islamic months in Arabic but since it's working in the desktop browsers I think it's fine!)

What went wrong?
The month is wrong! I get the localized version from the Georgian calendar. We don't have
أكتوبر
in the Islamic months.

Did this work before? No 

Chrome version: 63.0.3239.0  Channel: canary
OS Version: 7.1.2; GT-I9300 Build/NJH47F
Flash Version: 

The source code is available on GitHub: https://github.com/badersur/badersur.github.io/blob/8d102d5ccb6098ae0c285742eb1426abef3b32b3/app/scripts/main.js#L64

and you can see the behaviour in my website: https://bader-sur.appspot.com/ar/ (or https://badersur.github.io/ar/) at the bottom of the page.