Replaceing app brakes replication task?

system, scale Dragonfish
ERROR details

[EFAULT] Last full ZFS replication failed to transfer all the children of the snapshot apps pool@auto-2024-06-02_04-00. The snapshot Backup/Main/AppsPool/.system@auto-2024-06-02_04-00 was not transferred. Please run zfs destroy -r Backup/Main/AppsPool@auto-2024-06-02_04-00 on the target system and run replication again.


Had to trash that replication task and remake it.
This fixed it but im very confused on why.