Multiple code blocks in a single message are alternately syntax-highlighted

[Taywee]

Steps to reproduce

When I send this message:

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

```json
{ "foo": "bar" }
```

The result shows only every other one syntax highlighted.

Outcome

The event source shows that the html is correct, so I think this is a rendering bug, possibly all client-side:

{
  "type": "m.room.message",
  "content": {
    "msgtype": "m.text",
    "body": "```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n```json\n{ \"foo\": \"bar\" }\n```\n\n",
    "format": "org.matrix.custom.html",
    "formatted_body": "<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n<pre><code class=\"language-json\">{ \"foo\": \"bar\" }\n</code></pre>\n",
    "m.mentions": {}
  }
}

The expanded formatted_body:

<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>
<pre><code class="language-json">{ "foo": "bar" }
</code></pre>

Operating system

Fedora release 41 (Forty One)

Browser information

Firefox 133.0-1.fc41

URL for webapp

app.element.io

Application version

Element version: 1.11.86

Homeserver

matrix.org

Will you send logs?

Yes