There are few possible issues:
1. Your products are in draft – we dont sync qty for drafts
2. Amazon extension is not activated for your account.
3. Your GeekSeller SKU does not match with Amazon SKU.
4. Your Amazon API credentials are not correct.
5. You have incorrectly linked fulfillment nodes
Please contact us at firstname.lastname@example.org after you have checked all of these options and your account is still not syncing.