Analytics Software

I have a report to list top N sources of data. For my report, I have 12 prompt fields excluding the prompt for setting the top N value. The report is working fine with the 12 prompts some of which are constrained. All the prompts have "All Choices" as default values. The moment I add the prompt for the top N, the constrained prompts do not show any value in the drop-down. To provide a little more perspective, this is what I have done to create the top N prompt:

Used any random field and then changed the fx with hard value 1. Selected "Edit Box" for the control. The specific value has been set to 5. Using a presentation variable.

However, if I add this prompt with its own "Go" button, then I do not see the issue described above. I would not like to have 2 "Go" buttons.

Please let me know what I am missing here to make it work.

Thanks.

Bhusan