Cost not matching between Cost Management and Cost History for Azure EA starting in February 2023.
Azure Cost History data starting in February 2023 is collected directly from Cost Management API.
If the monthly total costs you are viewing in Cost Management do not match with Cost History monthly costs, the reason can be due to how the data is being retrieved in Cost Management. To rule this out, ensure you are retrieving the "actual cost" details instead of "amortized cost" details to fix the cost discrepancy that you are viewing.
Each metric affects how data is shown for your reservation charges.