Cannot connect to BLE

Hello!
I recently started using the Arduino Nano 33 IOT for project which requires connecting through bluetooth to an Android App (which I made in MIT App Inventor). But I can't connect it to any other device.
I was able to find it through a BLE scanner app at some point but I couldn't connect. Now I can't even do that.

I will leave my code below, any suggestion will be really appreciated. :blush: (this is not the code for my main project but I am just trying to test the connection).


#include <ArduinoBLE.h>
char c=' ';

BLEService SerialPort ("19B10000-E8F2-537E-4F6C-D104768A1214");
// BLE filter tester/incoming Value Characteristic
BLEUnsignedCharCharacteristic Pressure ("19B10001-E8F2-537E-4F6C-D104768A1214",  // standard 16-bit characteristic UUID
    BLERead | BLENotify); // remote clients will be able to get notifications if this characteristic changes

 
void setup() 
{
    Serial.begin(9600);
    Serial.print("Sketch:   ");   Serial.println(__FILE__);
    Serial.print("Uploaded: ");   Serial.println(__DATE__);
    Serial.println(" ");
 
 
    pinMode(LED_BUILTIN, OUTPUT); 
 
}
 
void loop()
{
      if (!BLE.begin()) {
    Serial.println("starting BLE failed!");
    while (1);}
    
      BLE.setLocalName("FILTER TESTER");
     // Read from the Bluetooth module and turn the LED on and off
    if (Serial.available()>0)
    {
        c = Serial.read();
        Serial.println(c);
 
        // The ascii code for 0 is dec 48
        // The ascii code for 1 is dec 49
        if ( c== 48) { digitalWrite(LED_BUILTIN, LOW); }
        if ( c== 49) { digitalWrite(LED_BUILTIN, HIGH); }
    }
}