RepNotify not working?

I do it like this in C++

it is the only way it works

//------------------------------------
UPROPERTY(ReplicatedUsing=OnUpdateTeamType)
ETeam TheTeamType = ETeam::None;
//------------------------------------
UFUNCTION(Server,Unreliable)
void SetTeamType(ETeam TeamType);

//------------------------------------

UFUNCTION()
void OnUpdateTeamType();
//------------------------------------

void UMaterialHandlerComponent::SetTeamType_Implementation(ETeam TeamType)
{
	TheTeamType = TeamType;
	SetTeamSkin(TheTeamType);
}
//------------------------------------

void UMaterialHandlerComponent::OnUpdateTeamType()
{
	SetTeamSkin(TheTeamType);
}
//------------------------------------