@ Html.CheckBoxFor Works on GET, but not on POST

I have the following model:

public class MEUViewModel
    {
        public List<Obj1> Obj1s { get; set; }
        public List<Obj2> Obj2s { get; set; }
        public int IDMeu { get; set; }
        public int IDMeu2 { get; set; }

        public bool Chk1 { get; set; }
        public bool Chk2 { get; set; }
        public bool Chk3 { get; set; }
        public bool Chk4 { get; set; }
    }

My POST method is basic signing:

[HttpPost]
        public ActionResult METODOPOST(MEUViewModel viewModel)
        {
          ...
        }

In my View I have the following Razor, one for each viewmodel bool:

@Html.CheckBoxFor(m => m.Chk1)

They are within BeginForm() , I will not put the whole code because when doing submit it falls into POST normally.

It generates the following HTML:

<input data-val="true" data-val-required="O campo Chk1 é obrigatório." id="Chk1" name="Chk1" type="checkbox" value="true">
<input name="Chk1" type="hidden" value="false">

When doing POST all four bools come False, regardless of whether they are checked or not.

• The two properties that have an object list come with normal bind.
• IDs (ints) come with normal binds.
• If I put true in any of the four properties in the GET method it will generate the HTML with the checkbox checked.

TEMPORARY SOLUTION UPDATE

After trying many things: - I put the HTMl in the hand, according to the link that Marconi sent - I tried the JS do Paulo - I tried Warleson's answer.

And nothing works, thank you all.

What I did to function temporarily was to change the signature of the method:

[HttpPost]
            public ActionResult METODOPOST(MEUViewModel viewModel, bool Chk1, bool Chk2, bool Chk3, bool Chk4)
            {

And I play the value of the variables in the model. It's not beautiful, but that's what worked. I'll leave the question open because I believe that a @Html.CheckBoxFor in such a basic structure should work in a simpler way, who knows, somebody else answers some better solution.