I'm also having this issue.
Previously I had been to the Wahaki and couldn't finish the "find evidence of the Leaden Key" quest. The Wahaki leader just tells me I can't step any closer, this was after I failed to read her soul with a check that happened before Ashen Maw. After Ashen Maw, I went to Neketaka and spoke to the Queen, she told me to check out the water shapers guild and I ended up killing the dragon there. The Queen was disappointed but then told me to blow up the powderhouse. I just ended up attacking and killing everyone in the powderhouse before planting the bomb and then successfully blaming it on someone else. Then talked to both the Queen and Prince, Queen said we're allies and that's it. No ships near Ukaizo, nothing else to move forward with in dialogue. I've never even seen the "Fruitful Alliance" quest show up.
Teacher, I can't open your saved game files within my game. I see your watcher's name show up as a bar behind my saved games list and it's unclickable.
https://imgur.com/a/Rbpt0TC I've compiled a list of other people's posts from reddit describing the same issue.