Incorrect avatar on Repository Commits page

Summary

In a few projects, the commits list shows incorrect avatars. In one of my repos, my avatar is correct everywhere else, but all of my commits show the default one. In another, it varies.

Steps to reproduce

In one of my private repos, every commit avatar is incorrect. I can privately provide information for it.

The best public example I could find is from here: https://gitlab.com/mkleehammer/spacemacs.d/commits/master

Notice that in the screenshot, there are two commits from the same day but they have two different avatars. It is possible that I committed them from different computers, so that is perhaps related.

Example Project

I wasn't able to reproduce it with a new project (https://gitlab.com/mkleehammer/avatar-test/commits/master).

What is the current bug behavior?

I see various avatars for my commits, without an apparent pattern.

What is the expected correct behavior?

I would expect my uploaded avatar to be displayed.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com