Trouble sending POST using SIM7000A

Hello all. I am working on a project that involves sending POST requests to a Twilio function using an Arduino Uno and a SIMCOM SIM7000A breakout board using AT commands. So far with the Uno, I can only POST an empty request that contains headers but no body. The following code is a test sketch where I am POSTing to a RequestBin repository.

#include <AltSoftSerial.h>

unsigned char data = 0;
AltSoftSerial SIM7000;
char incomingChar;


void setup() {

  Serial.begin(9600);
  SIM7000.begin(19200);

  // put your setup code here, to run once:
  SIM7000.print("AT+CMGF=1\r");  //put in text mode
  delay(100);
  SIM7000.print("AT+CGDCONT=1\"IP\",\"super\"\r"); //create profile.  "super" is APN for twilio super sim
  delay(1000);
  SIM7000.print("AT+COPS=1,2,\"310410\"\r"); //log on to AT&T network
  delay(5000);
  SIM7000.print("AT+SAPBR=3,1,\"APN\",\"super\"\r"); //create SAPBR profile.  same APN.
  delay(300);
  SIM7000.print("AT+SAPBR=1,1\r");
  delay(2000);
  Serial.println("Setup complete.  Module should be online and fast-blinking\n from successful SAPBR profile setup.\n Entering loop.  Send \"CHECK\" to test POST");
}

void loop() {


  SIM7000.print("AT+CMGL\r");

  if (SIM7000.available() > 0) {
    incomingChar = SIM7000.read();
    if (incomingChar == 'C') {
      delay(10);
      Serial.print(incomingChar);
      incomingChar = SIM7000.read();
      if (incomingChar == 'H') {
        delay(10);
        Serial.print(incomingChar);
        incomingChar = SIM7000.read();
        if (incomingChar == 'E') {
          delay(10);
          Serial.print(incomingChar);
          incomingChar = SIM7000.read();
          if (incomingChar == 'C') {
            delay(10);
            Serial.print(incomingChar);
            incomingChar = SIM7000.read();
            if (incomingChar == 'K') {
              delay(10);
              Serial.print(incomingChar);
              incomingChar = "";
              Serial.println(F("\nGOOD CHECK"));
              Serial.println(F("SENDING POST REQUEST NOW")) ;
              sendText();
              Serial.println("POST SENT");
              return;
            }
          }
        }
      }
    }
  }
  incomingChar = "";
  return;
}

void sendText()
{


  SIM7000.print("AT+HTTPINIT\r");
  delay(1000);
  getResponse();
  SIM7000.print("AT+HTTPPARA=\"CID\",1\r");
  delay(1000);
  getResponse();
  SIM7000.print("AT+HTTPPARA=\"URL\",\"http://engt62k9mgbgo.x.pipedream.net\"\r");
  delay(1000);
  getResponse();
  SIM7000.print("AT+HTTPPARA=\"CONTENT\",\"text/plain\"\r");
  delay(1000);
  getResponse();
  SIM7000.print("AT+HTTPDATA=100,5000\r\n");
  delay(100);
  getResponse();
  SIM7000.print("\"TEST MESSAGE\"\r\n");
  SIM7000.print("\r\n");
  delay(5000);
  getResponse();
  SIM7000.print("AT+HTTPACTION=1\r");
  delay(1000);
  getResponse();
  SIM7000.print("AT+HTTPTERM\r");
  getResponse();
}

void getResponse()
{
  if (SIM7000.available())
  {
    while (SIM7000.available())
    {
      data = SIM7000.read();
      Serial.write(data);
    }
    data = 0;
  }
}
//NOV 3 2020, note: need to include AT command AT+CMGD=0,4 for routinely deleting messages
//message storage limited and not automatically overwritten

I've attached the output on the Serial monitor titled "Test POST output.JPG".

I'm thinking that the problem lies between

SIM7000.print("AT+HTTPDATA=100,5000\r\n");

and

SIM7000.print("AT+HTTPACTION=1\r");

You can see on the output where it prompts for DOWNLOAD, but the "TEST MESSAGE" that I try to insert here doesn't go. I've also attached a screenshot of the RequestBin output to show that it's showing up as an empty POST with nothing but headers and a content length of 0.
When I've done similar POST requests using the same SIM7000A module with the same AT commands on PuTTY via USB, all I have to do is enter my text during the time specified in the AT+HTTPDATA command and hit enter. Whatever I enter during that time as it says "DOWNLOAD" shows up as the body of my POST. But I have as of yet been unable to do the same using the Uno.
Any help you can offer is much appreciated.

Update for those interested:

It turns out, the delay needed to be longer after
SIM7000.print("AT+HTTPDATA=100,5000\r\n");
I increased it to 1 second to give the SIM module time to catch up, and now my message body goes through to RequestBin. Still doesn't work for sending a POST body to my Twilio Function, but this is most of the way there. Just thought I'd leave this update in case anyone is having similar issues.