I had the same issue last week.. I went to replace the hatch gasket and no matter what I did, I always had a loop which wouldn't fit. Nothing I did made it fit. There are blue dots on the gasket which I assume are for alignment purposes but it made no difference. I gave it to my 18 year old and got him to fit it and he did it right first time. He didn't know I had failed multiple time so I just said "good job" and moved on.
It fits for sure so just keep trying.
EDIT: By the way my gasket was not split like yours is.