1 order with 2 items (same warehouse allocation and shipping method) generating 2 invoices??

[RAMC]

1st of all my apologises if this topic has been posted before (prior to this post I tried to find a similar case but was not able to find).

My shop is 2 days before launch. When earlier today testing an order consisting of 2 products I experience the awkward outcome that my PrestaShop (version 1.6.1.24) is generating 2 invoices...so 1 invoice for each order item. I checked if both products were allocated that the same warehouse and also check that the same shipping method is selected for both...still I don't understand why PrestaShop is outputting 2 invoice for 2 products whereas a single invoice is obvious preferred and the method forward.

 

Anyone out here can shed his/her light on this 1 ;-)?