Markdown Code Fences Broken

### Steps to reproduce

Type the following into the chat:

````
```python
def f(x):
pass
```
````

### Outcome

The following is a screenshot taken from element desktop. You can see that the first message looks perfectly fine (correctly rendered markdown). But the screenshot below (taken on my android phone) shows that the same message is not correctly displayed on android.

### Your phone model

Pixel 4a

### Operating system version

13

### Application version and app store

1.5.11

### Homeserver

#matrix:matrix.org

### Will you send logs?

No

### Are you willing to provide a PR?

No