FedEx Ground shipping wrong weight output and rate issue

Hello,

I set up a package weight 14 lbs on product data in admin, but FedEx company told me their system indicates it is 15.45 lbs. What happen? How can fix it?
The dimensions data are correctly receive by FedEx system.

The 2nd issue is, my online store calculates the shipping rate is much lower than my FedEx.com account. I setup FedEx account with account number, Meter number, and Auth key. But I can not get this low level rate from FedEx.com (with my account number login) .

Note: I got this FedEx module automatically when I install Opencart. (It seems like OC bult-in)

I called FedEx web service dept, they suggest me to contact the program developer.

Please help. Thanks in advance!

No OC version posted. Forum rules. However, see this solution: https://github.com/opencart/opencart/issues/6008 .