CSV import not importing back?

Hello again,

I have a question with this plugin. I exported reviews via CSV, then want to re-import them back, all of them via one category. It is only importing back ONE review per product ID, I have several? I do not understand this. In your documentation setup you have this mentioned in settings: Reviews per Step, and Start Line…I do not understand what these are?? they are set as the default, 10 and 2. Is this where the error is? Thank you.