Designs Tab doesn't respect right sidebar sizing

Summary

When refreshing in the browser with a designs tab, the container for designs does not properly size itself to the right sidebar. See gif below.

Steps to reproduce

Navigate to an issue with designs and click the designs tab. Refresh in your browser and see designs hidden under the right sidebar.

Example Project

What is the current bug behavior?

Window is not sized correctly and designs are hidden by the sidebar.

What is the expected correct behavior?

designs should not be hidden by the right sidebar