Having the exact opposite problem over here. With the latest version of Obsidian v1.0.0 there is no longer an horizontal scrollbar in the File Explorer Pane (i.e., allowing lateral movement). And I need it, I work with extremely nested files and folders.
I have tried to force it back through snippets but it was impossible, none of the Themes have neither the horizontal scrollbar. Does anyone know what happened to this and how to fix it? This was a really tedious change in UI.
PD. By the way, of course I have analyzed the problem in the Sandbox vault and exactly the same thing happens, the is no horizontal scrollbar at File Explorer, it does not seem that I am having a problem due to interaction with plugins, snippets, etc.