So, let's get back to the job. I use Chrome (latest version), and there is obvious bug.

1) Look [at this post][1].

2) Click to "edit" that post and without making any changes, just look at that post how it looks like in "Editor preview" page.

On my side, they look quite different (messed).

[![Enter image description here][2]][2]

  [1]: https://stackoverflow.com/a/56546442/2377343
  [2]: https://i.sstatic.net/xC5aA.png