There are two ways forward.
Option 1:
Clear the tax values by using feed rules, and then adding the tax settings in that account, instead of the feed.
https://support.google.com/merchants/answer/7450276?hl=en
https://support.google.com/merchants/answer/160162?hl=en
Option 2
Adding using feed rules and prepend the country code US
And check that the values look like this US::6.49:yes
Or US:80302:8.75
Etc
More info: https://support.google.com/merchants/answer/6324454
My recommendation, clear the rules, and setup up using Google Merchant Center Settings.