I am trying to get rounded corners for an image in Premiere Pro. I have added the crop effect and created a mask. The mask selection tool allows me to edit the rounded corners etc. but then nothing happens on playback. I can see the blue corners and can drag around the mask just fine, but it does nothing in the final project. I have searched online and it only seems people have this problem the other way around.
I am very new to premiere pro so I imagine this is something I'm doing wrong as opposed to a fault in the software, but I've tried everything from scratch and followed tutorials but nothing is working. It is infuriating.