TinyGSM GsmClient disconnects after multipart/form-data is sent

[nravanelli]

[X ] I have read the Troubleshooting section of the ReadMe

What type of issues is this?

[X ] Question or request for help

What are you working with?

Modem: SIM7000G
Main processor board: ESP32
TinyGSM version: latest
Code:

String fileType = "text/plain";
String content = "--boundary1\r\n";
content += "Content-Disposition: form-data; name=\"fileToUpload\"; filename=" + fileNameRemote + "\r\n";  // the fileToUpload is the form parameter
content += "Content-Type: " + fileType + "\r\n\r\n";
//after this, post the file data.
String closingContent = "\r\n--boundary1--\r\n";
client->println(String("POST ") + appCache.uploadFilePath + " HTTP/1.0");
client->println(String("Host: ") + appCache.host);
client->println("Keep-Alive: 300");
client->println("Connection: keep-alive");
client->println("Content-Length: " + String(content.length() + dataFile.size() + closingContent.length()));
client->println("Content-Type: multipart/form-data; boundary=boundary1");
client->println();
client->println(content);
if (dataFile) {  // start sending file content
  const size_t bufferSize = 1024;
  char buffer[bufferSize];
  while (dataFile.available()) {
    size_t bytesRead = dataFile.readBytes(buffer, bufferSize);
    client->write((const uint8_t *)buffer, bytesRead);
    fadeLED(3);
  }
  dataFile.close();
}
client->print(closingContent);
//GSMCLIENT DISCONNECTS HERE AFTER 1 SECOND
// Check HTTP status
char status[32] = {0};
client->readBytesUntil('\r', status, sizeof(status));
// It should be "HTTP/1.0 200 OK" or "HTTP/1.1 200 OK"
if (strcmp(status + 9, "200 OK") != 0) {
  Serial.print(F("[FILE UPLOAD] Unexpected response: "));
  Serial.println(status);
  deleteClient();
  return false;
}
// Skip HTTP headers
char endOfHeaders[] = "\r\n\r\n";
if (!client->find(endOfHeaders)) {
  Serial.println(F("[FILE UPLOAD] Invalid response"));
  deleteClient();
  return false;
}
  // Allocate the JSON document
JsonDocument doc;
// Parse JSON object
DeserializationError error = deserializeJson(doc, *client);
if (error) {
  Serial.print("deserializeJson() failed: ");
  Serial.println(error.f_str());
  deleteClient();
  return false;
}
deleteClient();
Serial.print(F("[FILE UPLOAD] Response: "));
Serial.print(doc["code"].as<int>());
Serial.print(" ");
Serial.println(doc["message"].as<String>());
if(doc["code"].as<signed int>() == 200){
  return true;
}else{
  return false;
}
}

Scenario, steps to reproduce

Load this code with an appropriate client connection on gsmClient, send a file, await http body.

Expected result

I expect the http response body to be received.

Actual result

When I use this code above to POST a file to my server, the GsmClient disconnects after sending the file. I do in fact receive the file on the server side, but I do not get the response body. Using the same code with WifiClient works as expected. The exact spot where the disconnect occurs is here:
//GSMCLIENT DISCONNECTS HERE AFTER 1 SECOND
I have diagnosed it is a 1 second disconnect.