If your marketplace/cart becomes disconnected from FarApp then none of your orders will be imported. It will also affect syncing products and fulfilling orders to the marketplace/cart as well. To resolve the issue search the FarApp support center for your connector under the Account Access section: https://support.farapp.com/hc/en-us/sections/360001635053-Account-Access. This will show you how to re-connect your marketplace/cart to FarApp.
If your marketplace, cart, or server is behind a firewall you may need to whitelist FarApp's IP addresses in order to allow FarApp to connect. This article lists FarApp's IP's: https://support.farapp.com/hc/en-us/articles/220139128-Quick-Reference-7-FarApp-IPs-to-whitelist.