Maybe someone has already said it, but 5.12 and flat octo with traditional Rx had flip issues. That's why 5.12a was released.
Originally Posted by Tarro
Today my recently completed Octo with a Cinestar gimbal flipped on me and crashed. I am running 5.12 firmware. Has this happened to anyone? I don't know why it happened, the octo was flying perfect, then all of a sudden it flipped to the left and crashed upside down.