<Transition> element exits without animating when content is changed with setState

[jelacs]

🤓 Question

Reposting my question as it has been closed without being solved.
I'm trying to create a list of expandable and collapsible items whose content comes from a single property in component state. The content is supposed to unmount on collapse as it is first removed from state. Animation works perfectly when entering but upon exit animation it just disappears (if expanded item is clicked to collapse) or is updated with the new state (if another item is clicked).
I could not post actual code but I tried to replicate the issue in this project.

I tried asking on StackOverflow but no luck. I hope someone here could help me find a solution. TIA!