Migrating Jira Cloud to Cloud with content attributed to Jira Service Management User fails

Issue Summary

Migrating Jira Cloud to Cloud with content (comment, attachment) attributed to a Jira Service Management user fails

This is reproducible on Data Center: No

Steps to Reproduce

1. Create site alpha.atlassian.net
2. Create site bravo.atlassian.net
3. Create Jira Service Management (JSM) project "Sierra"
4. Invite portal only user
5. Create issue via portal, SIE-1
6. As portal only user, comment on issue and upload attachment
7. Create Jira Software (JSW) project "Papa"
8. Move issue from JSM project to JSW project - issue key changes to PAP-101 and is now a JSW issue
9. Create cloud-to-cloud migration for project "Papa" from alpha to bravo
10. Observe failure

Expected Results

Migration completes successfully

Actual Results

Migration fails without warning message in GUI

The below exception is thrown in the xxxxxxx.log file:

Chunk Migration Error: DefaultEntityMigrationError(dateTime=2023-04-06T04:26:55.164718Z, entityId=mri:mig:jira:fileAttachment:12345, reason=IllegalArgumentException: User with account ID [qm:54321xxxx-f8f6-4e6a-a1f2-3b1d9c060ed8:xxxxxxxxx-8fee-45a0-973f-xxxxxxxxx] not found., actionToResolve=null, numDownstreamFailures=1, severity=ERROR)

File attachments and comments belong to accounts starting with "qm:"

Workaround

Nil