When use copy&paste for an object some of properties (like “RefDes”) have been selected even if was deselecteted in original object. It’s posible to fix this. If a large number of object was copied it’s a lot of work to select every one and make correction.
The RefDes is set up to automatically go on the schematic when posted or copied even when it is not on the copied portion. It was programmed in that way as for most applications that designation is needed. Unfortunately at this time there is no way other than manually removing it.