My Mask is not applying correctly can't work out why

Hi all,

I created a video a few months ago, I had to make a minor update to it today however when I rendered it I found that the mask that I had created was a bit funny, it wasn't applying on all sides of the rectangle, I'm no expert with premiere pro and I can't work out how to fix it, I'd rather not have to go through and recreate the mask for the entire video if possible.

I have attaches an image showing what's going wrong, if more info is needed let me know.

Thanks in advance 🙂