Why doesn't my Adobe spark (free) uploaded image fit

Hi there. First of all I couldn't find the Adobe Spark forum so I've slotted it in here for now - apologies.

My question concerns the use of the online free version of Adobe spark. I'm wanting to make some social media banners etc, and when I upload jpeg and pdf files of my logo they do not fit in the boxes provided in the templates. Zooming in and out etc and moving the borders doesn't help. I wondering whether this is just because it is the free version. Any help with this would be greatly appreciated Thank you