We can confirm this is a bug with VisualQuery input when used with Dashboard. We will issue a fix the next version of KoolReport. Meanwhile you could apply the following quick fix by opening the file {path to}/koolreport/visualquery/assets/js/visualquery.js and go to this part:

    vq.getInputValues = function () {
        ...
        inputs.forEach(function (input) {

then add the following line:

    vq.getInputValues = function () {
        ...
        inputs.forEach(function (input) {
            if (input.disabled) return; // add this line

Let us know how it works for you.