Auto advance for matrix question

Hi,
for the past 3 years I was using the following JS for simulating an auto advance on matrix questions.

Qualtrics.SurveyEngine.addOnload(function()
{
	/*Place your JavaScript here to run when the page loads*/
	var that = this;
var choices = this.getChoices( "radio" ).length;
this.questionclick = function( event, element ){
    var selected = that.getSelectedChoices().length;
    if ( choices  == selected )  {
       that.clickNextButton();
    }
}

});

This code worked like a charm - but stopped working about 2 months ago!

The current behaviour is:

Once all subquestions in the matrix are answered, the next button gets clicked and the next question is displayed. BUT also on the next question, the next button is clicked and this question is basically not displayed.

Is anyone aware of any changes made by Qualtrics, which could cause this behaviour?

Or is there a different solution for auto advance on a matrix question?

Thanks!

Manfred