Unable to select using mouse on heading and table together inside a macro

Problem description

When the heading and preceded by table afterwards, can't be selected using mouse, when the heading and table is inside macro body. The selection will somehow disappear when dragging the mouse to select the heading and table, cause user unable both heading and table together.

Steps to replicate

1. Open Confluence page editor, by editing or adding a page.
2. Create a panel macro, and put a heading followed by table, like the following screenshot.
   
3. Select the heading and the table together using mouse
4. Notice that somehow the selection will disappear as you drag the mouse down

Workaround

Use keyboard selection instead. Put the cursor at the beginning of heading, and press Shift button followed by the arrow button.