I have a double vented jacket where the back kinda tents up at the bottom just to the left of the seam. If you looked at it from the ground it is shaped like this /\. I have tried pressing it on both sides to no avail, is there any way to fix this or am I just bad at pressing?
Probably caused by a large shoulder blade that pulls the back up on one side. Pressing will have no effect if this is the cause. Can only guess without a picture.