When Invoicing with Back Orders the back ordered items are cancelled off the original order

SOLVED

Hi everyone,

I am new here and this is my first time to post. We use Sage Business Work 2018. Our company has never used the back order feature on Sage Business Works, but it is a feature that is very much needed right now. I tested it today, and I can't figure out how it works. When I invoice manually, I select the feature to allow back orders if items aren't available, then when I select the order a message pops up saying something to the effect that items aren't in inventory and if I continue the additional items will be back ordered. Then when I invoice, it invoices the items in stock but cancels  all the items on the order that are out of stock, and the order is closed.

Is there a preference I need to click? A step I am missing? 

We have numerous back orders I need to invoice on Monday so any help would be extremely appreciated.

Thanks.

Sheila