Sidbar not affecting window size

[saf-dmitry]

I think, your issue is already answered in this post:

Bug in Taskpaper? Sidebar can appear off-screen after clicking "Show sidebar"

I think this is intentional… though I admit maybe ill advised. The goal was to show sidebar without moving your document text on the screen. To get the more standard behavior go to TaskPaper > Preferences and make sure that “Sidebar > Maintain window size when Showing/Hiding sidebar” is checked. Then I think it will work as you would expect.