Reasons why customer- customer site is not collected to Planning

A sales order was not collected to Planning and upon checking I identified that the ship-to customer for that sales order is not collected to Planning. I verified this in Plan inputs > Maintain Supply Network model. I assume this is the reason why sales order was not collected to Planning.

What all could be the reasons for the customer to not be collected to Planning? The customer site is not having an end date, it's a newly created customer site which was created last month.

Any help appreciated