Limitation of 6 Requests followed in ajax

Question

Hello, I’m making an application where I make an ajax request to register in the bank, the request is working smoothly. However I noticed that only accepts up to 6 requests in a row without updating the page after this the server blocks. I am using the nodemon server running on Gulp.js

I wonder if this is a default limitation of ajax or browser ?

It is possible to parameterize to increase the number of requests followed or decrease ?

Here is the ajax request

    $('#form-aluno').submit(() => {
    let data = $('#form-aluno').serialize();
    console.log(data);

    const register = $.ajax({
        method: "post",
        url: "/alunos/register/save",
        dataType: "json",
        data: data
    })

    register.done((resposta) => {
        console.log(resposta)
    })


    return false;
})

Controller that records data/students/Register/save

    module.exports = () => {
    return {
        register: (req, res) => {
            data = {
                name: req.body.name,
                age: req.body.age,
                obs: req.body.age,
                turma: parseInt(req.body.turma_id)

            }

            console.log(data)

            Aluno.create({
                AL_NAME: data.name,
                AL_IDADE: data.age,
                AL_OBS: data.obs,
                AL_TURMA: data.turma
            })


            res.status(201)



        }
    }
}

NOTE: The Application is working I would just like to know about this request limitation for curiosity purposes and future projects