A network provides PDU sessions between wireless devices and data networks. UPFs in the network handle the user planes of these PDU sessions, while SMFs in the network manage the PDU sessions. The SMFs have dedicated interfaces for signaling sessions to the UPFs. In the occasion that managing of a PDU session has to be transferred from one SMF to another SMF, the first SMF has to release the signalling session with the UPF for the PDU session, and a second SMF has to re-establish the signaling session with the UPF for the same PDU session. To avoid that during the transfer of the management responsibility transfer the wireless device experiences a hick-up in the PDU session the first SMS includes a control element in the release message to the UPF, indicating to the UPF that the signaling session for the PDU session will be re-established by a second SMF, and that the UPF shall continue the handling of the PDU session till re-establishment.