HTML page, the copy button does not appear on the former and the copy button appears on the latter.

````
```shell
ls -a
```

```sh
ls -a
```
````

Do you know by what criteria this difference is occurring? (Or is there a list of names?)
2022-05-28T08:34:02Z
eitsupi
closed
Code blocks not considered code blocks?
https://github.com/quarto-dev/quarto-cli/issues/1007