The Insert Paragraph tool puts the text outside of the newly inserted paragraph tag. Here is an example:

1. Enter a line of text in an empty editor

2. Press the New Paragraph button

3. Type something when the cursor goes to the next line

4. Switch to HTML mode and you will find that the new text is inserted outside of the paragraph tag

<p>line of text</p>
<p>&nbsp;</p>
new line

The expect result should b:

<p>line of text</p>
<p>new line</p>