Chat Integrations plugin doesn't react on new posts

Since roughly the start of September 2026, our posts stopped being forwarded to Slack. The configuration was not changed at that time, and if I click the “Test” button, it creates the Slack message as intended. So the connection between Discourse and Slack is fine, it just does not create the messages when a new topic is posted.

Was there an update at that time that could have broken our configuration? Or perhaps was there a change to how Chat Integrations should be used that I’m not aware of?

Any help would be appreciated.