Additional info:
When trying to save, even if no changes have been made, it will tell us that the current version of the landscape streaming proxy is not the head revision from source control, even though we have just pulled the latest version. Saving these assets throws no errors and it allows overwriting of the file. If we exit the project, pull latest from depot, it will immediately overwrite our files we just saved.
This is preventing us from doing any edits to the landscape as all changes just get overwritten.