Open link in separate tab

Hi all,
I have a 2 fold question. I am working on a survey, which is displayed as part of an intercept. At some point one of the survey has a multiple choice question asking what would the respondent like to do next. 1. Take a survey or 2. Speak to an agent. If opt 2 is selected I have display logic that displays a text question with a piece of text saying "please wait while we redirect you". What is meant to happen next is that after this question the person is taken to end of survey. As part of the question I have included a piece JS code (code below) that will open the website contact us page in a separate tab. It is a requirement that the contact us page opens in a separate tab/window.
This is all working... for a while... without any known trigger, It "seems" that the survey gets corrupted and the all process fails when the recipient selects the opt2 and click next, which should trigger the process I explained above. Mainly it seems that the JS code, which allows to open the hyperlink in a new page is failing.
Question 1: When I try to troubleshoot, I see that in preview the JS is not working and the hyperlink is opening on the same window. Funny enough if I make a copy of the survey or export/import the survey, it works all well...Why a copy of a survey behave different after an import/export?
Question 2: Is there a better way to achieve what I am trying to do with the JS without using custom code?


Qualtrics.SurveyEngine.addOnload(function()
{
/*Place your JavaScript here to run when the page loads*/
function NewTab() { 
      window.open( 
              "http://www.website/contact-us/", "_blank"); 
    }
NewTab();

});