Jira Messages not Sending to Mattermost

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Summary
Creation of a ticket in Jira is not posting to Mattermost

Steps to reproduce
N/A

Expected behavior
N/A

Observed behavior
I have Jira integrated with Mattermost. I can create tickets and view tickets in mattermost either with /jira or with … next to chats.

What I cannot get working is when I create a ticket in Jira, it does not post to the subscription in Mattermost. No actions in Jira create messages in Mattermost.

I have the webhook assinged correctly, I followed the troubleshooting steps and FAQs for the plugin. I don’t see any error messages related to Jira/Webhooks.

Mattermost Version 5.39 (waiting for a stable 6+ to work in my environment)
Jira 8.20