Using cubase 8.0.5 on Mac 10.8.5. Noticed that the “Hide All Automation” key command or clicking “hide all” from the automation panel closes all folders that contain VST instrument returns. It’s easy to reproduce
new empty project
add a vst instrument
select “Hide All” from the automation panel
It will close the VST instruments folder for some reason. Also if you move the vst tracks into a different folder of your own it will close that as well.
I assume this is a bug because automation lanes are not tracks, they are opened from the drop down arrow on any track, including VST instrument channels. Folders are something complete separate from automation lanes and their are separate functions to close folders.