>>1769210Update to the latest beta version. That usually fixes the random export bugs that Inkscape has.
The headband is too flat at the corners. It means you are extending the handles farther out then they can handle. Most likely your upper and lower handles are uneven in order to try and compensate as well. In order to fix it, extend the handles at the 4 corners outwards enough (keeping them even and parallel) so that they still curve at the beginning. Then add two nodes in the middle to handle that part. Adjust the end point handles for consistency and that should do it.
