https://support.microsoft.com/en-au/topic/kb4568447-fix-automatic-seeding-failure-occurs-for-a-secondary-replica-in-sql-server-e1bec291-d04b-f664-21a2-087ba61637c8
KB4568447 - FIX: Automatic seeding failure occurs for a secondary replica in SQL Server - Microsoft...
FIX: Automatic seeding failure occurs for a secondary replica in SQL Server