If somebody forgets to add the shipping and created a new order for Misc, It is not able to synch these two orders.

For now, there is no way to sync this automatically because the shipping item and actual product items are separated between 2 orders. 

Customer Service and/or Shipping Clerk is responsible for contacting the Tech Team to synch these orders.

If an order is created, but the invoice has not been paid, you are able to ADD the MISC Shipping, and then pay the invoice.

If a client pays for a full order with store credit (zero balance at checkout) these orders will not synch to ShipStation either. 
 

Customer Service and/or Shipping Clerk is responsible for contacting the Tech Team to synch these orders.