A scrollbar is shown if the screen is narrow enough (as can be seen in the screenshot), but the content can't be scrolled.
This seems confusing, scrolling should either work (Preferred) or no scrollbar should be shown.
This. Or you'd need to word wrap code to see it. That'd look awful.
But a code block should also have a copy button similar to what ChatGPT would give you to the top right of the block too as it's somewhat difficult to copy entire blocks, sometimes missing and hitting text outside of the block. Seems like such a trivial suggestion to make that I won't bother. But hopefully they see this and add a copy button when they fix scrolling.