Mobile view - black space on top and bottom of presentation

Hi everyone,

I'm wondering if anyone has a quick fix to help solve my problem. I've published my storyline file from Storyline 3 to both wordpress and Moodle and while there is no issue viewing on desktop, the mobile view has a large amount of black space both above and below the slides. (I've attached images to show this - one shows the amount of space above and the other the amount of space below - I've hidden the content as it hasn't officially launched yet :) ) - we didn't seem to have this issue when publishing with storyline 2 - is there anything i can do?

Thanks so much for any help!