When calling Detach from the server, the object will get detached client-side, too - even if the Detach isn’t multicasted.
This also applies to Attach, and i’m assuming it’s an engine limitation and working as intended.
However, calling Detach on the server with “Mantain World Position” enabled will cause the client-side replicated object transform to world origin, and that’s causing us quite some headaches.
Setting ReplicatesMovement=true will keep the actor at the position where it was detached on the client. However this causes precission issues on our end as unreal by default allows MovementReplication only with up to two decimal numbers.