Okay, I am using the same version of Windows here. That is puzzling. There is no code that collapses the node in this context, so it must be something Windows is doing automatically for some reason.
I notice in your video that the folders are not showing the "count" of open windows, which is a default setting. Did you disable the "Show Count" option in the Treebar popup menu? The reason I ask is that I tested this with a clean install of mIRC, with no scripts/addons/etc., so all of the settings are set to defaults.
