@mattl There was a bug in android where apps can add themselves to a list of call-capable app multiple times, and Microsoft Teams was poorly coded so it would apparently add itself to that list multiple times a day
When calling 911, that list got parsed for some reason, and the parser would crash and therefore the 911 call would fail if there were thousands of entries of Teams on the list ?♀️
https://www.androidpolice.com/microsoft-teams-911-break-emergency-calls-android-explained/