Two things:
1. Working-from-home-during-global-pandemic-with-kids-and-spouses-and-roommates-and-not-ideal-setup isn't the same as working-from-home. Undoubtedly some people are less productive today.
2. Commits isn't necessarily a great proxy for productivity to begin with. For example, with greater focus comes less "oops I missed a unit test and broke the build" type commits, or even just more time to interactive rebase and clean up commits before pushing. "Go slower, you'll be done sooner."