Creating conditional timelines

[chen-goren]

Hi everybody,
I have a timeline with a language selection trial at the beginning. After that trial, I have 3 almost identical timeline versions, with some language modifications in their texts (prompts). I"'m trying to code my script so after the language selection there will be a switching function that will push the correct timeline according to the user's selection. this is my code for the timeline selection:
"var switchTimeline = {
type: jsPsychCallFunction,
func: function() {
var languageCode = jsPsych.data.get().last(1).values()[0].language; // Retrieve the language code from the last trial's data
if (languageCode === 1) {
timeline.push(...timelineMALE);
} else if (languageCode === 2) {
timeline.push(...timelineFEMALE);
} else if (languageCode === 3 || languageCode === null) {
timeline.push(...timelineOTHER);
} else {
console.error("Invalid language code:", languageCode);
}
}
};
timeline.push(switchTimeline);"
As you can see, after the user selects a language, it is coded as 1, 2, or 3. In the switchTimeline element, I try to continue the experiment with the corresponding timeline (timelineMALE for 1, timelineFEMALE for 2, and timelineOTHER for 3 or not answering).

I have also tried a different switch function: 
"var switchTimeline = {
type: jsPsychCallFunction,
func: function() {
    var languageCode = jsPsych.data.get().last(1).values()[0].language; // Retrieve the language code
             switch (languageCode) {
              case '1':
                  timeline.push(...timelineMALE);
                  break;
              case '2':
                  timeline.push(...timelineFEMALE); 
                  break;
              case '3':
                  timeline.push(...timelineOTHER); 
                  break;
              default:
                  console.error("Invalid language code:", languageCode);
          }
      }
  };
  timeline.push(switchTimeline);"

Unfortunately, after this language selection trial, the screen stays blank and the experiment gets stuck. 
I would appreciate any help. Thanks!