White borders appearing on custom shortcut icons on iOS Home Screen

Okay so I just wanted to make a shortcut with a custom image for a new app because I want my homescreen to look nice, but apple has apparently added these random white borders on the side? I can’t seem to get rid of them and it looks REALLY ugly against my very dark toned homepage (it’s meant to look like a starry sky). Is there any way to fix this issue? I’ve never had this problem before (as you can see all shortcuts but one look perfectly fine), so clearly this happened in some recent update.