I also experienced something similar and exactly the same as what you said. when I was making a mindmap using the FigJam Ai feature to generate ideas from the mindmap branch, it was initially smooth but something like this happened. I tried to duplicate the FigJam board but it was still the same, then I tried to use a different email to login to Figma and create a new FigJam board and it worked, it turned out that the FigJam Ai could be used on my different email… I assume that means there is something wrong with my experience on the first Figma email account.