Why does the store with the highest forecast not receive a product?

There are a few reasons such as the store having enough stock or a store being 'blocked'

The store already has enough stock to cover its forecast while other stores in the scenario have a substantial forecast but not enough stock

Indeed, the aim of store transfers is to balance the stock of products between stores to complete their size sets, taking into account their demand forecast over the planning horizon.  

The store with the highest forecast for a given product can be blocked

In this case, "BLOCKED" will appear (first picture) at the bottom left of the Store picture. The product can be blocked for any of the following reasons (second picture):

• Apply replenishment block: product block in the Visual Merchandiser field.
• Block recently moved products: are the store / product combinations that have been blocked because the planning horizon is still valid in the previous transfer scenarios.
• Block recently introduced products: product implemented in the store for a shorter period of time than that considered in the scenario ("Range" and "Number of days").

The store with the highest forecast for a given product is not receiving any inbound trip

Therefore, it makes no sense to create a new trip just for moving one product.