CircleCI is misatributing commits and build triggers

For some reason, CircleCI seems to be misattributing commits (and their resulting builds):

All of these commits were authored by me (the one with the dog avatar), but the oldest one was attributed to me, while the 3 newer ones were wrongly attributed to a coworker.
I clicked on each of these commits, and the GitHub page for the commit correctly attributes them to me.

What could be causing this? I noticed this happening with at lest 2 different projects.