Tree does not collapse reliable

[JuliusRuppert]

Describe the bug
When clicking multiple times on a tree item, the subitems do not collapse reliable.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Domino UI Demo page'
2. Click multiple times on a tree item that is not a leaf, e.g. Layout
3. The tree does not collapse reliable on each click

[vegegoku]

I am trying to reproduce this but I cant, I can see sometimes there is a little delay, but that was intentional, since the animation needs to be completed before trigger the next collapse/expand otherwise we get messed up calculations for the actual elements height.