ArduinoHTTPClient times out (HTTP_ERROR_TIMED_OUT = -3) even though server sends 200 HTTP Response about tinygsm HOT 1 CLOSED

// main.cpp
TinyGsm modem = cellFunctions.modem;
TinyGsmClient gsmClient = cellFunctions.gsmClient;

// cellFunctions.h
class CellFunctions
{
public:
        CellFunctions(HardwareSerial &serialGsmRef, HardwareSerial &SerialATRef, StreamDebugger &debugger);
.
.
.

        TinyGsm modem;           // instance of TinyGsm modem class
        TinyGsmClient gsmClient; // instance of the TinyGsm client class to use with mqtt
};

// getMQTTEndpoint.cpp
bool MQTTEndpoint::getMQTTEndpoint(Client &client)
{
    char final_url[256]; 
    sprintf(final_url, "http://%s/api/firmware/%s/", domain, apiKey);
    bool endpoint_found = false;
    while (!endpoint_found) 
    {
        HttpClient http(client, domain, 80);
        http.setTimeout(10000);
        int err = http.get(final_url);
        if (err != 0)
        {
            Logger.logMessage(LOG_LEVEL_ERROR, "HTTP GET not successful");
        }
        err = http.responseStatusCode();
        Logger.logMessage(LOG_LEVEL_DEBUG, "The HTTP Response code is: %d", err);
        if (err >= 300 || err < 200)
        {
            Logger.logMessage(LOG_LEVEL_ERROR, "Failed to get MQTT Endpoint due to bad HTTP response code");
            delay(30000);
            continue;
        }
        String payload = http.readString();

//main.cpp
TinyGsm modem = cellFunctions.modem;
TinyGsmClient gsmClient(modem);  // here i actually pass the modem to the gsmClient before using the client to call getMQTTEndpoint