When the editor window with the template is active, the left sidebar is partially hidden. Is this intended?
Which theme do you use?
I don’t experience this on my test instance:
This was happening to me as well, but after updating to latest today it is working properly.
Hello! This bug works for all my themes, for example Material Design Theme, Air Theme. I tried updating the site to the latest version as @davidkingham said, I also tried disabling all plugins and theme components, but nothing helped 