Here's an example:
Arizona v. California, 373 U.S. 546 (1963) wherein the Supreme Court held Congress acted within its realm of authority when it created a plan to manage and operate the Colorado River even though it had previously granted consent to the Colorado River Compact whose purpose was to assist in the management and operation of the body of water.
A duly enacted federal statute or treaty passed after the interstate compact is entered into may supersede or abrogate provisions of the interstate compact, even if the interstate compact, on its face, says otherwise.
This is mostly because:
Federal law is supreme over state law, and
A later enacted law or treaty may overrule any previously adopted law or ...