Seeing a new popup which is changing my applied style in my word documents

Not seen this before but see this window pop up if hit return on an empty line in my document and then have a new style and spacing. See image below. Top shows the box and current default document formatting.
The image below shows the result of hitting enter twice. I am not using this in a novel, but in a project to keep info on how to write a novel.
Not sure what is happening.

Solved my own issue, accidently slipped into scriptwriting mode somehow. Hit Ctrl + 8 to get out.