POST is empty depending on the site I use

I have a project in Codeigniter that is in a folder within the domain. The folder structure is as follows:

  

/ domain / Web / project /

I'll call domain and project because of the client / site name

I can access the site in two ways: www.myspace.com/project or www.project.com .

However, in all% w_that I do, the variable forms is empty when I fill in the www.projeto.com.br site (which should be correct because the client wants access as a site isolated from its root). If I fill out the forms from the site www.mydomain.com/project the variable $_POST receives the data normally and I can proceed with the navigation.

Is there a way I can get the two URLs to receive the POST normally as one?

Here are the codes for $_POST and controller, for a form of login:

<form method="POST" action="sac/nova_conversa">
    <input type="hidden" name="lojaID" id="lojaID" value="<?= @$lojaID; ?>" />
        <p>
            <label>Nome:</label>
            <input type="text" name="nome" id="nome" />
        </p>
        <p>
            <label>Telefone:</label>
            <input type="text" name="telefone" id="telefone" />
        </p>
        <p>
            <label>E-mail:</label>
            <input type="text" name="email" id="email" />
            <input type="submit" value="Entrar" class="entrar" />
        </p>
        <?PHP if ($this->session->flashdata('errors')) { ?>
            <p class="erro"><?= $this->session->flashdata('errors'); ?></p>
        <?PHP } ?>
    </form>

Controller:

public function nova_conversa() {
    if ($_POST) {
        $data["nome"] = $this->input->post("nome");
        $data["telefone"] = $this->input->post("telefone");
        $data["email"] = $this->input->post("email");

        if (($data["nome"] == "") or ($data["telefone"] == "") or ($data["email"] == "")) {
            $this->session->set_flashdata('errors', 'Digite seus dados');
            redirect("sac");
        } else {
            $usuarioID = $this->sac_model->novo_usuario($data);

            $data["lojaID"] = $this->input->post("lojaID");
            $conversaID = $this->sac_model->nova_conversa($usuarioID, $data["lojaID"]);

            $this->session->set_userdata('chat_usuarioID', $usuarioID);
            $this->session->set_userdata('conversaID', $conversaID);

            redirect("sac/abrir_conversa");
        }
    }
}

Thank you!