From your description, that doesn’t really sound like a drawer. It’s more like a second column that can auto-show and hide. If the right column appears while you can still operate the left one, that means the right column doesn’t overlay the left, it has its own dedicated space.

The question then is: when the right column is hidden, should the left column expand to fill the gap? If it does, the content on the left will keep shifting in height as the width changes, which makes browsing less pleasant. If it doesn’t, then hiding the right column doesn’t seem all that necessary, which is basically how it works now.