We have a problem with our stores where neither the negotiated nor published UPS rates match what they actually are at our shipping terminal. We use weight based shipping, and UPS XML.
If I send an 8lb package to Illinois, the site calculates UPS Ground at $12.60 when live rates are on. For the same shipment, our actual negotiated rate is $9.08 and the published rate is $14.34. If I turn off the live rates, the site shows it as being $21.00.
I have no idea what is causing this issue or how to fix it. If I try turning off UPS XML, then all of the UPS shipping methods completely disappear.
I am fine with doing either negotiated rates with a markup, or published rates with a discount, but the rates need to be much more accurate before it will work.