I had the exact same as that! I went to my doctor and he said it’s fine!! Nothing to worry about the corners just take longer to heal as that’s where the stitch is in a knot! This was what mine looked like. X
Is it at the outside of your scar and did you have drains?
I have the same, it’s where my drain was as the hole is left slightly open there to accommodate it (kind of a stitch missing if you know what I mean), so takes slightly longer to heal x