GridView is triggered again when clicking on it while the keyboard is open

I have some code for the Item of a GridView.
The GridView's Item has LineareLayout so that it must execute first and when the CheckBox is clicked it should be visible. The LineareLayout has two TextBoxes and when clicked on it the keyboard is shown to accept text input.

My adapter is:

public override View GetView(int position, View convertView, ViewGroup parent)
{
    ////set Gone in start
    LinearLayout llToGone = convertView.FindViewById<LinearLayout>(Resource.Id.ll_add_count);
    llToGone.Visibility = ViewStates.Gone;
    ////Handle checkbox
    CheckBox chb = convertView.FindViewById<CheckBox>(Resource.Id.chb_prod);
    chb.SetOnClickListener(new CheckBoxClick(context,llToGone));
}

public class CheckBoxClick :Java.Lang.Object, IOnClickListener
{
    Activity act;
    LinearLayout ll;
    public CheckBoxClick(Activity ctx,LinearLayout l)
    {
        act = ctx;
        ll = l;
    }

    public void OnClick(View v)
    {
        CheckBox ctv = (CheckBox)v;
        if (ctv.Checked == true)
        {
            ll.Visibility = ViewStates.Visible;
        }
        else
        {
            ll.Visibility = ViewStates.Gone;
        }
    }
}

My problem happens when I click on the TextBox to add the text and the keyboard is open:
the adapter is rerun and the CheckBox is gone with checked="False".

Why does that happen and how to preserve the state of it?