Hi Fillip,
When a secondary node falls out of sync with the primary federation server, minor replication blockages can be addressed by examining the replication state via Get-AdfsSyncProperties and forcing an immediate database poll by restarting the local federation service using Restart-Service adfssrv. If deep configuration corruption or broken trust states prevent successful replication, the fully supported recovery path is to re-initialize the node by executing the Add-AdfsFarmNode cmdlet with the -OverwriteConfiguration parameter. This command safely discards the corrupted local configuration database, authenticates against the primary server using the farm service account, and performs a complete fresh synchronization of all federation settings, policies, and relying party trusts.
Hope this answer has brought you some useful information. If it did, please hit “accept answer”. Should you have any questions, feel free to leave a comment.
VPHAN