You will get notifications after a few days, such as 6 or 7 days. You cannot get notifications of a software update immediately after its release, even if connected to a strong Wi-Fi network.
Or you can set a schedule to update your phone on the calendar. Since the phone got an update on 17th June, which was the third Monday of the month, now every third Monday your phone has a chance to get an update. Just simply create an event on the calendar, repeating it on the third Monday of every month.
