Welcome.
On Macs, users type option enter for a paragraph return and command option enter for a line break. Don’t know the keystrokes for other operating systems. I could see that the file had paragraph returns at the end of the broken lines (not line breaks), so I only had to search and replace those. It helps to see invisible characters to understand the construction of the text. Don’t know what apps show invisibles in Windows. Word? Scrivener? Notepad?