Copy a `blockQuote` → paste it into `/new-topic`’s `text/plain` `textarea` → switch to the previewer → becomes `pre > code`

Contribute Bug
1

In a manner nigh identical to what t/392035 describes, when I duplicate:

> `blockQuote`

…into my clipboard, from the previewer, when I paste it into the editor, it becomes pre > code, using CommonMark indentation syntax:

    `blockQuote`

Context

My use case is working around the undermentioned:

…as is demonstrated in: