lost notifications

[sdarwin]

Describe the bug
Our slack channel has been subscribed to a repository.
90% of the time, when I open an Issue in the GitHub repository, there is a message in the Slack channel.
10% of the time, when I open an Issue in the GitHub repository, nothing is reported.
So, a subscription exists, and it's mostly working.
However, messages are being dropped.

It is a concern, if the loss rate is more than.... 1%. Right?

The issue could be on the github side or the slack side. Either one.

It's not certain at all that this codebase is the cause of the problem. Maybe some other backend system. You could collaborate (slack + github) to find a way to track delivery success rates end-to-end.

To Reproduce
Steps to reproduce the behavior:

1. Go to Issues, such as https://github.com/integrations/slack/issues
2. Click on "New Issue"
3. Create an Issue
4. Nothing happens in Slack

Expected behavior
A message appears in the Slack channel.

Desktop (please complete the following information):

• OS: Ubuntu 22.04 Desktop
• Browser Chrome
• Installed Slack: 4.40.133 169 latest/stable slack✓ -

[kaylareopelle]

I'm also missing notifications for new issues and comments on issues. The first known occurrence of this was today.