Project Output issues

Hi Captivate friends.

I have built a responsive e learning project using fluid boxes at the default 1024 x 627 size.

When I upload and view the project on my LMS system (Learning Pool) on a screen with resolution of roughly 1920 x 1024, the output project maintains its built size and does not adapt to the size of the screen.

Previously when I built and published in HTML5 using breakpoints the output size did adapt to the maximum size of the screen no matter how big, of course is was not fully responsive on smaller screen.

How can I create a fully responsive project that fills the size of a bigger screen but continues to be responsive on smaller screens.

I wonder if the issue is of captivate source, LMS or maybe a browser issue.

Really impressed with fluid boxes, they have taken some getting used too but my knowledge is growing all the time.

Thanks so much in advance for your replies.

Best wishes

Russell