Contributors with the same name are not listed properly on the webpage

Summary

There are two contributors with the same name on our project. But only one of them is listed on the contributors web page.

Example Project

Here is the link of our project that shows the problem: https://gitlab.com/petsc/petsc/-/graphs/master

There are two "Hong Zhang" with different email addresses. But this page displays only one of them and email address changes from time to time.