Typically an addendum supersedes that portion of the original contract that the addendum specifically addresses. That's a general rule. Whether it applies in your situation depends on the details in the contract, addendum and the surrounding circumstances.

Does an addendum override a contract?

The document will include any additional information or requests that the buyer did not put into the original purchase and sale agreement. The language in the addendum has the ability to override the original terms of the agreement. ... An addendum makes the contract more streamlined and easier to read.

Is an addendum to a contract legally binding?

An addendum can be created by persons other than the ones who signed the original contract. Amendments are considered part of a contract until it is next negotiated, while an addendum is a legal and binding part of the contract.