Okay, you can use UObjects not AActors.
In your owner class implementation of ReplicateSubobjects must be looks like this:
bool AMyGameMode::ReplicateSubobjects(class UActorChannel *Channel, class FOutBunch *Bunch, FReplicationFlags *RepFlags)
{
bool WroteSomething = Super::ReplicateSubobjects(Channel, Bunch, RepFlags);
for (auto& item : Items)
WroteSomething |= Channel->ReplicateSubobject(item, *Bunch, *RepFlags);
return WroteSomething;
}
Replicate every item individually