Using Fusion for simple drop shadow on .png issues

Hi,
firstly I could be going about this all wrong,
but I thought I found a simple way to add a shadow or glow to a .png. but it only works partially.
I open the png in fusion and add drop shadow,
then return to edit page and it's there but if I then want to move the logo to another section of the screen it gets cutoff.
Is there anyway when opening in Fusion that it opens as full resolution of the footage not the .png?
firstly I could be going about this all wrong,
but I thought I found a simple way to add a shadow or glow to a .png. but it only works partially.
I open the png in fusion and add drop shadow,
then return to edit page and it's there but if I then want to move the logo to another section of the screen it gets cutoff.
Is there anyway when opening in Fusion that it opens as full resolution of the footage not the .png?