Email notifications not being received for custom notifications (specifically: new release notifications)

Summary

I've been excited for Gitlab to support custom notifications to monitor some repos for just new releases, but it hasn't worked for me, and no email notifications ever arrive.

Steps to reproduce

Here are example subscriptions which have had multiple releases I haven't been email-notified about:

https://gitlab.com/AuroraOSS/AuroraStore/-/releases shows there was a release as recently as a week ago.

What is the current bug behavior?

No email gets sent.

What is the expected correct behavior?

I should get an email for every new release.

Example project

https://gitlab.com/gitlab-bronze/release-notification-test

Output of checks

This bug happens on GitLab.com