Slack Connection went down

Hi,

We have both email and Slack notifications set up to notify project managers when creative requests come in.  Last Thursday I renamed the Slack channel, and the PMs stopped receiving notifications through Slack.  I received an error message stating the rule was invalid, so I updated to connect with the new Slack channel name, thinking this would resolve the issue.  Unfortunately it hasn't.  Any idea what might be happening and how I can solve?

Thank you.