I just threw a minimal test case and it worked as expected on my end. If you’re still experiencing issues, it might be best if you can share a link to a paste or repo containing your extension’s source.
Hi @dotproto, I figured out what the problem was: My default_title string under browser_action was too long, so the badge got pushed too far to the right and I couldn’t see it. I shortened the default_title, now it’s working.