Here is a brief overview of the 2 treaties involving ownership of the Panama Canal. For those who like contract law, you can see the complexities but a clear meeting of the minds. The spirit of the agreements surrounded perpetual use. That would require "meaningful" use. These fees they put on us nearly render our use impossible. Trump is right, Panama is in violation of every aspect.
https://history.state.gov/milestones/1977-1980/panama-canal