@hhfgeg It seems you are not using English, I've helped translate the content automatically. To make your issue understood by more people and get helped, we'd like to suggest using English next time. 🤗
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[Bug] magicType clicking on different formats is not valid immediately

I think this is a documentation issue - stack is not explained, just mentioned.
In fact it is not meant to be a switch, but a toggle button between bars and stacked bars. A typical usage for stack is this official example where it toggles between grouped and stacked bars.
So the solution is - either explain this in the docs, or rewrite the code to make it a switch button. The latter is kind of tricky though, because only grouped bar data would be "switchable". Simple bars cannot be stacked, so what would the button do if someone is using it in such context?