Every time the section macro is edited in the wysiwyg editor, and extra newline is added between the opening section macro tag, and the first column tag.

Eg

{section}
{column}
a
{column}
{column}
b
{column}
{section}

when edited and saved in the Rich Text Editor, will save the following:

{section}

{column}
a
{column}
{column}
b
{column}
{section}

And a second edit will produce

{section}


{column}
a
{column}
{column}
b
{column}
{section}

This might be a bug in the Layout Macros plugin or it might be a generic renderer problem when any open macro tag is placed on the line after another open macro tag.