Hey, thanks for the detailed report. This is a known regression. After backend changes around April 24, Slack automations only trigger correctly for the automation creator, and bot messages aren’t processed at all. We’re already tracking this internally, but I can’t share an ETA for a fix yet.
For context, there’s a parallel thread with the same symptom: Automation with Slack trigger no longer replying to any users but automation creator
For now, the only workaround is the one you already found: manually reposting from the automation creator’s user account. We’ll post an update in that thread as soon as we have one.