Spoiler text and collapsible sectiona do not work well

Paste to post editor:

Spoiler:
>! [Hidden Spoiler Text] This is the spoiler content.
> Optionally with more lines

Collapsible section:

<details>
<summary>Click to expand</summary>

These details <em>remain</em> <strong>hidden</strong> until expanded.

<pre><code>PASTE LOGS HERE</code></pre>

</details>

>! [English Version]
>
> Hello beauties!
>
> I must say I’m very happy, as this year we’re celebrating four parties in Ecuador.
Text still inside.
Text still inside 2.
>
> This year, we’re having a party in the Ecuadorian capital, Quito. 
This is my third party in Portoviejo, the second one sponsored by PizzaDAO providing pizzas and drinks. 

Text outside the sopiler.

Denser results (wrong) there are missing spoiler buttons and the content is always visible:

Expected as in Hive blog: