there must be an issue with looking up the quote.
in the bindings panel, expand the binding group for UPS Shipping, and add the full request and full response bindings, this will contain info on what the problem is.
to retain the selections that are made, you will need to store them in session variables using the eCart Set session value behavior, then use the session variables as the intial values for the form elements.
to add a set session value behavior, go to the server behaviors panel, click the plus button and select eCart -> General -> Set Session Value. for the trigger and value, click the lightning bolt and select the form element. For the name, use the same name as the form element to make it easier to identify.