I am using the data that comes with the event directly, and that seems to work more reliably: void wifiEventHandler(System_Event_t *event) { switch (event->event) { case WIFI_EVENT_SOFTAPMODE_STACONNECTED: case WIFI_EVENT_SOFTAPMODE_STADISCONNECTED: { char mac[32] = {0}; snprintf(mac, 32, MACSTR &qu...