Ask HN: Emergency Alerts – Some phones get it, some dont?

As some may have heard there were tornados and flooding in NY/NJ and many areas of the northeastern US. Over a dozen died.

My mom, wife, and I were all sitting at a dining table together when this all happened yesterday evening. My mom's Android phone received over a dozen Emergency Alerts on the tornados and floods.

My iPhone received three alerts. My wife's iPhone received one only.

All our phones have all Notifications enabled, including Emergency Alerts and Public Safety Alerts. We were all on the same WIFI network.

Whey would there be such big differences in what each of us received?