It's changing so fast and I personally don't use them, but one I saw was loom
https://github.com/socketteer/loom it's a free version and I think the author currently uses a non-public continuation of the project but I'm not sure. It's the one they used in the research behind the simulators essay
https://generative.ink/posts/simulators/I guess it's not primarily a mind map tool that adds AI as an afterthought. It's a GPT explorer that could possibly be used for mind mapping.