Problem with fedex shipping rates with free shipping items

Hello there,

I have face a problem while i add one free shipping item and one non free ship item in cart page, the problem is , when I add the non free ship item the fedex shipping rate is $10 at the same time i continue do shopping and next time i add the free shipping item then the fedex shipping rate is get rise, What i want is when any one add one free ship item and one non free ship item then the fedex shipping rate will stay constant that is $10.


Thank you

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