Chrome: root DIV not converted to P with enter after LI ending in inline tag

In chrome, the newly-created root container isn't properly converted from a DIV to a P if it follows a list item ending in an inline tag (e.g. `strong`).

### Reproduction

Start with:
```
<ol>
  <li><strong>1|</strong></li>
</ol>
```

Cursor is indicated by the `|`.
Hit enter twice and the newly-created root container doesn't get converted from a div to a p like it should.

If you remove the strong tag and repeat the same thing, it does get properly converted.
What's the reason for `null`ifying?