I'm trying to create a model in Blender. It is symmetrical over the X and Y axes, so I used a mirror modifier over X and Y axis. However, when I apply the mirror, the edges don't "loop" and faces are created on the inside. This causes issues when UV unwrapping because on these edges seams are created even though I didn't mark them as seams.
I tried to prevent this from happening by turning off "clipping" in the mirror modifier and I've tried removing inside faces and non-manifolds.