未能将换行符转换为符号

I'm trying to convert newlines to breaks. But for some reason I can't get this to work. I did various tests, and I know the function is being executed, and that the variable passed to the function is definitely a string. It's weird that this does not work. Since I use exactly the same function for double escaping newlines before I send it to the server. I have tried a lot of things, and do not understand why this does not work.I'm trying to convert newlines to breaks. But f