Código persiana y millis

He verificado tu código y encontré algunas discrepancias.
Yo empecé de 0 y esto funciona bien

/*
 *  This sketch demonstrates how to set up a simple HTTP-like server.
 *  The server will set a GPIO pin depending on the request
 *    http://server_ip/gpio/0 will set the GPIO2 low,
 *    http://server_ip/gpio/1 will set the GPIO2 high
 *  server_ip is the IP address of the ESP8266 module, will be 
 *  printed to Serial when the module is connected.
 */

#include <ESP8266WiFi.h>
#include <ArduinoOTA.h>


const char* ssid     = "Surbyte";
const char* password = "password";

IPAddress ip(192,168,1,227);
IPAddress gateway(192,168,1,1);
IPAddress subnet(255,255,255,0);

const int rele1 = 13;
const int rele2 = 12; 
int val, val1 = 0, val2 = 0; 
int periodo = 40000;  
byte temp = 0; 
unsigned long tiempoAnterior = 0;  
int periodo2 = 40000;  
byte temp2 = 0; 
unsigned long tiempoAnterior2 = 0;  


// Create an instance of the server
// specify the port to listen on as an argument
WiFiServer server(1088);

void setup() {
  Serial.begin(115200);
  delay(10);

  // prepare GPIO2
  pinMode(2, OUTPUT);
  digitalWrite(2, 0);
  pinMode(rele1, OUTPUT);
  pinMode(rele2, OUTPUT);
  digitalWrite(rele1, HIGH);
  digitalWrite(rele2, HIGH);
  pinMode(4,INPUT);
  
  // Connect to WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  WiFi.config(ip, gateway, subnet);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  ArduinoOTA.setPassword((const char *)"1234");
  Serial.println();
  Serial.println();
  Serial.print("Conectado a ");
  Serial.println(ssid);
  Serial.print("IP:");
  Serial.println(ip);
  Serial.printf("MAC Address = %s\n", WiFi.softAPmacAddress().c_str());
  Serial.print("Puerto: 1088");
  Serial.println();
  Serial.print("Ordenes: arriba/abajo");
  Serial.println();
  Serial.print("Ordenes: arribatodo/abajotodo");
  Serial.println();
 
  ArduinoOTA.begin();
  // Start the server
  server.begin();
  Serial.println("Server started");

  // Print the IP address
  Serial.println(WiFi.localIP());
}

void loop() {
  // Check if a client has connected
  WiFiClient client = server.available();
  if (!client) {
    return;
  }
  
  // Wait until the client sends some data
  Serial.println("new client");
  while(!client.available()){
    delay(1);
  }
  
  // Read the first line of the request
  String req = client.readStringUntil('\r');
  Serial.println(req);
  client.flush();
  
  // Match the request
  int val1 = digitalRead(rele1);
  if (req.indexOf("/arribaon") != -1)  {
      digitalWrite(rele1, LOW);
      digitalWrite(rele2,HIGH);
      Serial.println("Subiendo");
      temp = 0;
      temp2 = 0;
  } 
  if (req.indexOf("/arribaoff") != -1)  {
      digitalWrite(rele1, HIGH);
      Serial.println(".");
  }
  
  int val2 = digitalRead(rele2);
  if (req.indexOf("/abajoon") != -1)  {
      digitalWrite(rele2, LOW);
      digitalWrite(rele1,HIGH);
      Serial.println("Bajando");
      temp = 0;
      temp2 = 0;
  }
  if (req.indexOf("/abajooff") != -1)  {
      digitalWrite(rele2, HIGH);
      Serial.println("Stop");
  }

  if (req.indexOf("/abajotodo") != -1)  { 
      tiempoAnterior=millis();  
      temp =1;
      digitalWrite(rele2,LOW);  
      digitalWrite(rele1,HIGH);
      Serial.println("Bajando persiana");
  }

  if ((millis()>tiempoAnterior+periodo)&&temp==1){  
      digitalWrite(rele2,HIGH); 
      temp = 0; 
      Serial.println("Persiana completamente bajada");
  }

  if (req.indexOf("/tiempo") != -1)  {
      Serial.println(millis());
      Serial.println(tiempoAnterior);
  }
  if (req.indexOf("/arribatodo") != -1)  { 
      tiempoAnterior2 = millis();  
      temp2 = 1;
      digitalWrite(rele1,LOW); 
      digitalWrite(rele2,HIGH);
      Serial.println("Subiendo persiana");
  }

  if ((millis()>tiempoAnterior2+periodo2)&&temp2==1){  
      digitalWrite(rele1,HIGH);  
      temp2 = 0;  
      Serial.println("Persiana completamente subida");
  }

  // Set GPIO2 according to the request
  val = val1;
  digitalWrite(2, val1);

  // Prepare the response
  String s = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n<!DOCTYPE HTML>\r\n";
  s += "<html><p>GPIO is now :";
  s += (val)?"high":"low";
  s += "</p>";
  s += "<p>Rele 1      :"; 
  s += digitalRead(rele1)?"OFF":"ON";
  s += "</p>";
  s += "<p>Rele 2      :"; 
  s += digitalRead(rele2)?"OFF":"ON";
  s += "</p></html>";

  // Send the response to the client
  client.print(s);
  delay(1);
  Serial.println("Client disonnected");

  // The client will actually be disconnected 
  // when the function returns and 'client' object is detroyed
}