[Resolved] Can add product on back office order

Background of the issue:
I am trying to edit an order as an administrator from the back office and add a specific product.

Symptoms:
When I write the first letters of the product or full product name, no result is found.

Questions:
Why can't I find the product when I type the first letters or full name?
Is there a setting I need to adjust to add products to an order from the back office?