tag disappears

In WordPress, I write articles using Markdown notation using JP Markdown of the plugin.
In the fixed page, I write it by HTML rather than Markdown, but only posting the <p> tag disappears when posting an article.

With JP Markdown enabled, please write and post as follows.
`html
<div>
??<p>
????Sample sample Sample
????Sample sample Sample sample Sample
????Sample sample sample
??</ p>
</ div>
`
Then, only the <p> tag and </ p> tag disappears clearly in the source of the surface article page, as shown below.
`html
<div>

????Sample sample Sample
????Sample sample Sample sample Sample
????Sample sample sample

</ div>
`
Next, when switching the plug-in’s JP Markdown to the invalid state and transitioning to the article writing screen again, only the <p> tag and </ p> tag disappears clearly as shown below. Once you enable JP Markdown again, you will return to the <p> tagged state.

`html
<div>

????Sample sample Sample
????Sample sample Sample sample Sample
????Sample sample sample

</ div>
`

I was tried and error to disable automatic formatting because of the automatic shaping function of wpautop, but I can not solve it by any means. In the fixed page, it is impossible to do automatic formatting directly with HTML, in the contributed article only want to use the basic Markdown, occasionally want to use the article of HTML striking (occasionally Markdown only if it is impossible) is what I want to do.
If you understand something, please tell me it.
Thank you.