Insert a code fence with any content. Don’t add a new line after the code fence and make sure that nothing comes after the code fence.
Collapse the header using the toggle button.
Expected result
In both editor and preview mode, the header should collapse everything under it up to the header of the same size or until the end of the page.
Actual result
When the header is collapsed (only in editor mode), it inherits the background of the code fence instead of keeping the normal background when it is not collapsed.