Hello, team!
I have noticed this issue on the API docs page, which it seems to also be using Bryntum Grid.
I am on a 16' MacBook (viewport inner size 1728x998) and noticing this consistently on both Chrome and FIrefox.
Steps to reproduce:
navigate to https://bryntum.com/products/grid/docs/api/Core/data/Store
after load, click on the above "Core" node, and after collapse you will notice 2 "Core" nodes
click again on the "Core" node, you will notice that the second one collapses