lovefromisrael Do you see the alert in the history? And the others who were around you, do you know if they also have Android phones, and do the emergency alerts show up in the history?
As far as I know, GrapheneOS has only made small changes to how this works. You can see the history here. The last two are made by a member of GrapheneOS, the rest are from upstream AOSP. They only added the ability to toggle off certain alerts. So, unless I'm mistaken, I'd expect if any phones running Android receive emergency messages, phones running GrapheneOS should be no different.