Issue Summary

If a user has a private shared-connect channel in Slack, and the @Statuspage App had been added in one slack workspace, and the other slack workspace subscribes to a Statuspage, it will not add the StatusPage App on the subscribing slack workspace and thus not configure the subscription.

Steps to Reproduce

1. Create two Slack workspaces
2. Create a channel in the Slack workspace One (S1) as a Private channel.
3. Share the channel with Slack workspace Two (S2)
4. In accepting the invite on the S2 side, set the channel to private.
5. Confirm the channel sharing was completed, and both workspaces had access to, and were in the channel.
6. On SP1, add the Statuspage app (/invite @Statuspge) . Confirm the app was
   present in the channel, and was visible by both the SP1 & SP2 Workspaces
7. Subscribe to a Statuspage Slack subscriptions, specifiying the Shared Connect Channel in the SP2 Workspace.
8. We are in the situation, where the APP is installed in SP1, and the Subscription was made to SP2.
9. You will see that the Statuspage App is not added to SP2, and the Channel is not integrated with Statuspage.
10. Create an Incident in Statuspage - No notification will appear in channel.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available