Situation : The Client issued the addendum after the contractor submitted their rate.
This occurred because of the contractor/tenderer failed to key in the rate for addendum. The client issued the addendum after the contractor submitted their rate but the contractor did not update their rates at created addendum item and straight submit their rates.
To prevent similar issues happens in the future, please make sure the contractor/tenderer updates their rate for addendum items promptly. This ensures that the latest revisions of amount are accurately captured.