Issue Summary

When a Jira Data Center app uses the App Migration Platform's Forge Object Store path to upload migration data directly from DC to Forge storage during the onMigrationStarted event, the operation fails for Forge apps. The Forge Object Store path is not functioning as expected, making the migration pathway unavailable.

This affects any vendor implementing DC-to-Forge custom field or data migration that relies on the AppCloudForgeMigrationGateway to write to Forge Object Store as part of the migration flow.

Steps to Reproduce

1. Implement DiscoverableForgeListener on a DC app with an onMigrationStarted handler that writes to Forge Object Store via AppCloudForgeMigrationGateway.
2. Deploy the Forge counterpart app and install it on a Jira Cloud site.
3. Trigger a DC-to-Forge migration via JCMA.
4. In the onMigrationStarted Forge trigger, attempt to write or retrieve data via the Forge Object Store migration path.
5. Observe the failure.

Expected Results

The Forge Object Store migration path works consistently across all supported Atlassian Cloud regions.

Actual Results

The migration fails. The Forge Object Store path is not available or not functioning correctly, blocking the entire migration for any app that relies on this mechanism. Vendors and their customers have no viable alternative path to complete the migration.

Workaround

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