A method performed by a shared Distributed Unit, DU, (502; 602; 702; 802; 902) for either (a) two or more base stations or (b) two or more network slices for the same base station, where the two or more base stations or the two or more network slices comprise separate Central Units, CUs, (504, 506; 604, 606; 704, 706; 804, 806; 904, 906) and the shared DU comprises shared resources that are shared by the two or more base stations or the two or more network slices, the method comprising: receiving (Fig. 5A/6A, step 1; Fig. 7, step 1; Fig. 8/9, step 1) a Radio Resource Control, RRC, message from a User Equipment, UE, (500; 600; 700; 800; 900), the RRC message being an RRC Setup Request message, an RRC Reestablishment Request message, or an RRC Resume Request message; sending (Fig. 5A/6A, step 2; Fig. 7, step 2A; Fig. 8/9, step 2aA) a first DU-to-CU message to a first CU (504; 604; 704; 804; 904) from among the separate CUs of the two or more base stations or the two or more network slices, the first DU-to-CU message comprising an RRC container that comprises the RRC message; either i) obtaining (Fig. 5A/6A, steps 7a-9a; Fig. 7, step 5A; Fig. 8/9, step 3aA) an indication that the first CU is a wrong CU for the RRC message or ii) determining (Fig. 5B/6B, step 6b) that the first CU is a wrong CU for the RRC message; and upon obtaining the indication that the first CU is a wrong CU for the RRC message or determining that the first CU is a wrong CU for the RRC message, sending (Fig. 5A/6A, step 10a; Fig. 5B/6B, step 8b; Fig. 7, step 2B; Fig. 8/9, step 2aB) another DU-to-CU message to a second CU (506; 606; 706; 806; 906) from among the separate CUs of the two or more base stations or the two or more network slices, the other DU-to-CU message comprising an RRC container that comprises the RRC message or a related RRC message related to the RRC message. receiving (Fig. 5A/6A, step 1; Fig. 7, step 1; Fig. 8/9, step 1) a Radio Resource Control, RRC, message from a User Equipment, UE, (500; 600; 700; 800; 900), the RRC message being an RRC Setup Request message, an RRC Reestablishment Request message, or an RRC Resume Request message; sending (Fig. 5A/6A, step 2; Fig. 7, step 2A; Fig. 8/9, step 2aA) a first DU-to-CU message to a first CU (504; 604; 704; 804; 904) from among the separate CUs of the two or more base stations or the two or more network slices, the first DU-to-CU message comprising an RRC container that comprises the RRC message; either i) obtaining (Fig. 5A/6A, steps 7a-9a; Fig. 7, step 5A; Fig. 8/9, step 3aA) an indication that the first CU is a wrong CU for the RRC message or ii) determining (Fig. 5B/6B, step 6b) that the first CU is a wrong CU for the RRC message; and upon obtaining the indication that the first CU is a wrong CU for the RRC message or determining that the first CU is a wrong CU for the RRC message, sending (Fig. 5A/6A, step 10a; Fig. 5B/6B, step 8b; Fig. 7, step 2B; Fig. 8/9, step 2aB) another DU-to-CU message to a second CU (506; 606; 706; 806; 906) from among the separate CUs of the two or more base stations or the two or more network slices, the other DU-to-CU message comprising an RRC container that comprises the RRC message or a related RRC message related to the RRC message.