Thanks tpartner for resolving this question for me!

@Joffm: No, I did not put the array question and the short text question that should be merged in different question groups - as my lss exports also show.
But I have several questions where I want to merge an array question with a short text question to provide the "other" option for the participants to type in. And those are in different question groups and I want to display them group by group. As I understand tpartner, this is not possible with JavaScript because they all have to be displayed on the same page.

Please correct me, if I am wrong!

And I also resolved my mistake with the array-numbers with checkboxes. I counted wrong, I am sorry (td.answer-item:eq(2) instead of (3))
It works.

So for me, all questions resolved now. Thanks again for your help!

Dear all,

I am encountering the same issue, I am using Version 3.15.9+190214 provided by my university.. I don't understand what happened as initially it was displaying perfectly.I have a very similar type of question but could not figure out what I am missing. I would be very grateful for any help/input provided.

Thank you,

Giulia 

I have not the least idea. Might be a glitch in the database ( I know this from other tools I worked with)
So you have to be creative and try things.
Create this group in a second survey and see if it works there.
Therefore i only created a new group and moved all questions to this one.
Works.