Sometimes Pinch loses connecting to your connected account system, and needs to be restored to enable functionality, and data syncing.
When this occurs, Pinch will send an email to your primary contact address alerting you to the disconnection.
A secondary way to be alerted of this is by reviewing the "Status: Inactive" at the top of the dashboard or from the Integrations tab. 
To restore connection to your accounting system, head to the Integrations tab in Pinch, and click the "Refresh Link" button. This will prompt you to restore the connection between Pinch and your chosen accounting system. Follow the one-screen prompts and allow the system to perform a fresh sync.
If this process has been successful, your Status will change to "Active - Last sync less then 10 minutes ago"