Incorrect rendering of question box with multiple solutions in generated notebook

When creating a tutorial with a question box that contains multiple solution dropdowns the automatically generated Jupyter notebook doesn't generate the question box properly causing the cell to render incorrectly.

Here is a basic question box that replicates the issue:

```markdown
> Question Title
>
> Question 1
>
> >
> >
> > Solution 1
> >
> {: .solution}
>
> Question 2
>
> >
> >
> > Solution 2
> >
> {: .solution}
>
> Question 3
>
> >
> >
> > Solution 3
> >
> {: .solution}
>
{: .question}

Text after the question box doesnt get rendered correctly either
```

Rendered in the tutorial:


Rendered in the Jupyter notebook


The source code of the notebook cell:

```markdown

Question: Question Title

Question 1

👁 View solution

Solution

Solution 1

Question 2

👁 View solution

Solution

Solution 2

Question 3

👁 View solution

Solution 3

Text after the question box doesnt get rendered correctly either

```

---

It looks like its generating a `````` tag after every ```{: .solution}``` (not including the first one), however since the only opening blockquote tag is at the start of the question box this causes the rest of the cell's rendering to break.