If you find that all your Ebay orders aren't syncing into your Web Ninja site, or you accounting package. It's possible that your Ebay token needs to be renewed.
If you create a ticket here: https://webninja-support.zendesk.com/hc/en-us, Support will be able to look into it and determine if this is the issue. Please provide Ebay login details so they can renew the login for you and you can sync through orders again.