Which expert can analyze why CSDN cannot wrap lines today?

Who analyzed why CSDN cannot wrap lines today? this is the first line. this is the second line. this is the fourth line (the third line is empty). This is the link to the bug I submitted: http://bbs.csdn.net/topics/390532303? Who can analyze why CSDN cannot wrap lines today?
This is the first line
This is the second line

This is the fourth line (the third line is empty)

This is the http://bbs.csdn.net/topics/390532303 of the link where I submitted the BUG

Why is this happening? CSDN bugs cannot be shared:
------ Solution --------------------
If it is php, there is no issue with the nl2br function.
If this function is not available in other languages, you need to replace the code with handwritten characters.
It is estimated that he wants to reduce the burden on the server and put the replacement in the browser for execution. But the code is not written.