A first base station is configured to execute instructions of the first BS transmitting a first interface message to a second BS for a secondary node change from a third BS to the second BS, wherein the first interface message does not comprise the first SCG configuration; the first BS receiving a second interface message responding to the first interface message, from the second BS, wherein the second interface message comprises a second SCG configuration; and the first BS transmitting a radio resource control message to a communication device, wherein the RRC message comprises the second SCG configuration and an indication indicating release of SCG.