Lightbox slide not displaying in custom Full Screen mode

Hi, we have added a tab to the player to switch between full screen and normal mode (screenshot attached - player tabs). We have used a javascript to trigger this on the 'View/Exit Full Screen' text in the screenshot.

We have also added a Lightbox slide on the 'Course Instructions' text in the screenshot.

Now, when I press F11 and viewthe Full Screen mode, I can see the Lightbox slide on clicking the 'Course Instructions' text. However, if I view the Full Screen mode by clicking the 'View/Exit Full Screen' text, I cannot see the Lightbox slide on clicking the 'Course Instructions' text. That clearly means the custom javascript is causing some issues for the Lightbox slide in full screen mode. 

We have used the Javascript in 2 places - Slide Master and Player tab. I am attaching their screenshots as well. Kindly assist to resolve this.