Were you alone or wtih other players?
With other Players
Description
When assigning a replicated object to a player, the assigned player is set to the object’s authority. This doesn’t work if the object was previously spawned and returned to the replicator, with the authority being the replicator’s authority. Set Authoirty doesn’t work either.
I've encountered this issue when spawning and assigning a laser pointer component to a player when they join. If a player left, returning the laser pointer, and a new player joined, they wouldn't become authority of the laser pointer they spawned and assigned themselves to.
– bucketman