Occasionally the connection with a store fails and Shipstation stops importing orders. That's all it takes is to press the "update all stores" button and it fixes itself. However, we are not notified when orders stop importing, and therefore sometimes days go by without us knowing that shipstation is not importing and fulfilling orders, and so orders end up going out late.
Shipstation needs to add the functionality for a notification email when this happens! You can't expect users to monitor shipstation 24/7. This is so basic and should be straightforward to implement. Please add it asap.
Since I don't know your business situation, this might not be helpful, but could you try making it a habit just to "update all stores" once or twice a day? We currently have 5 stores connected and never experience the connection failing for days, and I haven't seen other discussion about it here on the Community, so I can't imagine they'll make it an ASAP priority.