When processing orders you might come across the "Rate returned by carrier quote service does not match rate returned by carrier ship service. Quote rate XX.XX and shipping rate: XX.XX" error.
This error is related to FedEx providing different values between the original quote, and the rate provided when processing (shipping) the order. This control's strictness can be configured to ignore discrepancies, allow certain margins, or fully block orders with any kind of discrepancy.
When this error message is shown, it means that the current discrepancy is within the selected level of strictness.
To change the strictness level you will have to:
1. Access Maintenance and select Carriers
2. Click the Carrier for which you'll add the account to from the list
3. Click the Accounts tab
4. Edit the Account related to the case
5. In the Carrier section select a different option from Quote vs Shipping Rate Validation, taking into account the possible values and effects as described in the Optional Section, point 3 of How to set up a FedEx Baseline account (REST) [Step-by-Step guide]
6. Press Save to confirm the change
NOTE: If discrepancies are persistent, contact FedEx support, since these are provided directly by FedEx via API.