If a new untitled Writer file is created, and not named before Libreoffice attempts to save a backup copy, the program saves repeated copies so rapidly that the program itself becomes difficult to use.  Especially true if the file is large (cut and pasted text.) It turns into a struggle to actually use the dropdown menu to name it and stop the obsessive saving of multiple copies (got up to about 3500 copies of 'untitled 1' once, when the phone rang just as I'd created it).  

On the plus side - it's been a long time since I've created an 'untitled 2' file.