Select conditional field not working correctly

Hey,

I'm facing the following issue with the webform module:

I have a select field where users can select between 1 and 3 periods.
I have 6 other select fields, 2 for each period, where users can select some details.

I've set conditional rules where I define that -for each period- if the period is not selected, it should hide the 2 select option matching that period.

When I open the webform, and no periods are selected, the 6 subselects are hidden.
When I select the periods, the suboptions are shown.
When I deselect the periods, the suboptions remain shown.

Is there anyway I can debug this to find where this is going wrong?