Missing how it works?

Perhaps I’m missing how is this supposed to work?

I’ve installed it on my 4.3 site.

I set the global option:
off (turn off WordPress’ auto-formatting)

I create a new post, and type (in the textual editor) <p>hi</p><p>bye</p>, I switch to the visual editor and I see the expected two paragraps; but when I go back to the text editor, the p tags are gone, and a (textual) newline appears instead.

https://wordpress.org/plugins/wpautop-control/