I realized that I have not been receiving emails from Kagi Feedback, even though I have selected "Daily digest" under the Email Digest Frequency setting:

I switched to "Send each notification immediately" and received a digest email with all notifications since July 2024 (it is November 2025 when I write this). I couldn't determine any obvious mistake in my Notification settings, so I think that's a bug.
I expect emails would be sent once someone posts in the topic I am subscribed to, but that did not happen.