A communication device for handling a full configuration, comprising: at least one storage device ; and at least one processing circuit , coupled to the at least one storage device , wherein the at least one storage device stores, and the at least one processing circuit is configured to execute, instructions of: establishing a packet data unit, PDU, session identified by a PDU session identity, ID, with a first network node; the communication device being configured with a first data radio bearer, DRB, identified by a first DRB ID and associated to the PDU Session or the PDU session ID, by a first base station, BS, connecting to the first network node; receiving a first radio resource control, RRC, message from the first BS; releasing a first service data adaptation protocol, SDAP, entity associated to the first DRB and releasing at least one of a first packet data convergence protocol, PDCP, entity associated to the first DRB, a first radio link control, RLC, entity associated to the first DRB and a first logical channel associated to the first DRB, when the first RRC message indicates the full configuration and comprises a first DRB configuration, wherein the first DRB configuration comprises a second DRB ID and the PDU session ID; adding a second DRB according to the first DRB configuration and associating the second DRB to the PDU session; and communicating first data associated with the PDU session on the second DRB. at least one storage device ; and at least one processing circuit , coupled to the at least one storage device , wherein the at least one storage device stores, and the at least one processing circuit is configured to execute, instructions of: establishing a packet data unit, PDU, session identified by a PDU session identity, ID, with a first network node; the communication device being configured with a first data radio bearer, DRB, identified by a first DRB ID and associated to the PDU Session or the PDU session ID, by a first base station, BS, connecting to the first network node; receiving a first radio resource control, RRC, message from the first BS; releasing a first service data adaptation protocol, SDAP, entity associated to the first DRB and releasing at least one of a first packet data convergence protocol, PDCP, entity associated to the first DRB, a first radio link control, RLC, entity associated to the first DRB and a first logical channel associated to the first DRB, when the first RRC message indicates the full configuration and comprises a first DRB configuration, wherein the first DRB configuration comprises a second DRB ID and the PDU session ID; adding a second DRB according to the first DRB configuration and associating the second DRB to the PDU session; and communicating first data associated with the PDU session on the second DRB. establishing a packet data unit, PDU, session identified by a PDU session identity, ID, with a first network node; the communication device being configured with a first data radio bearer, DRB, identified by a first DRB ID and associated to the PDU Session or the PDU session ID, by a first base station, BS, connecting to the first network node; receiving a first radio resource control, RRC, message from the first BS; releasing a first service data adaptation protocol, SDAP, entity associated to the first DRB and releasing at least one of a first packet data convergence protocol, PDCP, entity associated to the first DRB, a first radio link control, RLC, entity associated to the first DRB and a first logical channel associated to the first DRB, when the first RRC message indicates the full configuration and comprises a first DRB configuration, wherein the first DRB configuration comprises a second DRB ID and the PDU session ID; adding a second DRB according to the first DRB configuration and associating the second DRB to the PDU session; and communicating first data associated with the PDU session on the second DRB. <EOS>