Integrated Notebook Course Player Tab for learners to take notes and access throughout course

Hi,

I'm trying to add an integrated notepad into my course that learners can access throughout to input their own notes at any point as and when they desire. 

To achieve this, I've created a Notebook Slide with a text entry field which I've inserted into a scrolling panel so there's ample room for text.  Then, I've added a lightbox to the course player as an additional tab (from the Features tab in player properties).  I've called my tab 'Notebook' and the lightbox trigger opens the correct 'Notebook' content slide.  When I preview my project and click on my newly added 'Notebook' tab it works perfectly on the first visit.  However, if I continue on with the course and try to click on it again to continue adding notes, it comes up blank and the navigation is disabled.

I've removed the navigation from my notepad slide and have also set the slide properties to 'resume saved state when revisiting so previous notes won't be lost.  What am I missing?  Can anyone help please?