Google Drive API Upload no response - arduino

Question

I tried to upload an image (JPG) from an Arduino to Google drive using the API.
Sometimes it works (I do the POST request as described in the guide and send all the bits) and I receive 200 OK, but sometimes, after sending all the bytes, google drive does not give me any response.
any suggestions?
Here there is the part of the code which dose the Upload (note I pasted only the "problematic" part).
- Sometimes the while cycle finishes because I receive the 200 response.
- Sometimes I receive no response and so I start again to send the image.
In
while (millis() - startTime < 15000 && !received)
I tried to wait up to ten minutes, but no response
Serial.println("Token request has been succesful. Starting upload");
bool succesful = false;
// I have obtained the uploadID, now I start uploading
String location = "https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable&upload_id=" + uploadID;
received = true;
while(!succesful){ // I upload until it is successful
// I stop the previous client session, because now I start a new one, to do the PUT request and upload the file
client.stop();
// Upload request
if (client.connect("www.googleapis.com", 443)) {
client.println("PUT " + location + " HTTP/1.1");
client.println("User-Agent: Arduino Camera");
client.println("Content-Length: " + String(image.size()));
client.println("Connection: close");
client.println();
while (image.available()) {
client.write(image.read()); // Here I send the bytes of the image
}
Serial.println(".");
image.close();
received = false;
} else {
Serial.println("Connection failed");
received = true;
}
// Listening to the response
startTime = millis();
String code = "";
while (millis() - startTime < 15000 && !received) { //try to listen for 5 seconds
int i = 0;
while (client.available() && i < 12) {
received = true;
char c = client.read();
Serial.write(c);
code = code + c;
i++;
}
// HTTP 200 OK
if (code == "HTTP/1.1 200" || code == "HTTP/1.1 201")
{
while(client.available()) {
char c = client.read();
Serial.write(c);
}
Serial.println("\nUpload succesful");
succesful = true;
// client.stop();
return succesful;
}
if (!received) {
client.stop();
Serial.println("\nUpload interrupted. Starting a new session");
// I have to open image again
image = SD.open(filepath, FILE_READ);
}
}