DOI points to messed-up URL

Running OJS 3.2.1.1. DOI plugin is enabled and working. However, any given DOI points to a very messed-up URL. For instance:

. we have an article at https://gradusjournal.com/index.php/gradus/article/view/143

. its DOI is https://doi.org/10.47627/gradus.v5i2.143

. clicking on the DOI, or submitting the DOI to doi.org, points to https://gradusjournal.com/index.php/gradus/announcement/view/3%23pkp_content_nav/index.php/gradus/about/index.php/gradus/issue/archive/index.php/gradus/about/submissions/index.php/gradus/about/submissions/index.php/gradus/about/editorialTeam/index.php/gradus/about/submissions/index.php/gradus/login/index.php/gradus/index/index.php/gradus/about/submissions/index.php/gradus/about/privacy/index.php/gradus/article/view/143

How can I fix this?

Luiz Cláudio