There are a number of possibilities.
The two most common are 1) printhead overheatings and 2) the plastic "Z" strip is damaged.
First, I would lower the "heat/pressure" setting from "normal" to "light" or "lighter". I would also try a different vinyl setting such as "Quantum 2000".
Also, check the plastic "Z" strip located next to the printhead. The strip is white white or off-white in color.
If the crease continues, try running your Edge without the "Z" strip that is located on the right-hand side of the printhead.