A Dance with Death can't be completed. Suffering from the same issue here. Can't sail with the Principi to Ukaizo. I almost tried everything to give the god damn signal in order to Principi sail with me but nope, couldn't find a way. I hope this is my fault but doesn't seem like it. If there's a solution, a way, even if it's a cheat at this point, please enlighten me. I am really frustrated.
Thank you.