esp32 reconnection after power surge - esp32

Question

I have an esp32 as STA in my network, collecting sensor data, that publishes through my wifi AP to my home network. Everything was working fine until we had a general power surge in the neighborhood. When power came back the esp32 was out of the network. I had to recycle its power to let it re-establish connection. Is there an explanation for this? Most probably it came up much faster than the wifi or the mqtt broker did. Could this be the issue? If this is the issue, is there a way to postpone booting of the esp32 just after wifi network and mqtt is available?
Edit: I return to my original post to add some code that I used.
void setup() {
Serial.begin(115200);
delay(10);
WiFi.mode(WIFI_STA);
// Configures static IP address
if (!WiFi.config(local_IP, gateway, subnet, primaryDNS, secondaryDNS)) {
Serial.println("STA Failed to configure");
}
// Connect to Wi-Fi network with SSID and password
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
// Print local IP address
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
...
client.setKeepAlive( MQTT_KEEPALIVE );
client.setServer(mqtt_server, 1883);
client.connect(aHostname);
if (!client.connected()) {
Serial.print("mqtt status in setup: ");
Serial.println(client.state());
reconnect();
} else {
client.setCallback(callback);
Serial.print("mqtt status in setup: ");
Serial.println(client.state());
client.setCallback(callback);
client.setKeepAlive( MQTT_KEEPALIVE );
}
Also if mqtt broker is lost there is a reconnection attempt in loop:
void loop(){
if (!client.connected()) {
reconnect();
}
..
}

Answer 1

If it's a question of ESP32 booting faster than the WiFi access point, then this has a very simple solution. Retry the WiFi connection in ESP32 until it succeeds. Then do the same with MQTT. If you think about it, the device is useless without WiFi&MQTT connections so feel free to just keep retrying forever (or until it's successful).
In your case the MQTT broker's retry in the loop() should be an obvious example of to add a similar retry for the WiFi. Since I don't use Arduino and I don't currently have the time to read the WiFi module's documentation, I'll leave the implementation to you.