Flow video generator problem

I'm working on a project with a talking character in Google Flow video generator. At some point my character started to sing the words that I'm writing as regular speech. It started one month ago, and now when I came back to this project again she is still singing. Whatever I'm trying to do doesn't help. I tried to start new project, I tried to write in prompt "no music on the background", "no singing", "she speaks regularly", I tried to upload a new picture of this character, I tried to write super long and super short prompts, regular and JSON prompts. I tried to animate her in another project with another character that doesn't sing. NOTHING WORKS.
Have you ever faced this problem and is there a solution? Seems like it's a bug that impossible to solve, but this is working project and I need somehow to overcome it.