diff --git a/openair2/F1AP/f1ap_ids.c b/openair2/F1AP/f1ap_ids.c
index 009517510e..a69c21d050 100644
--- a/openair2/F1AP/f1ap_ids.c
+++ b/openair2/F1AP/f1ap_ids.c
@@ -60,14 +60,14 @@ void cu_init_f1_ue_data(void)
   pthread_mutex_unlock(&cu2du_mutex);
 }
 
-bool cu_add_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data)
+bool cu_addmod_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data)
 {
   pthread_mutex_lock(&cu2du_mutex);
   DevAssert(cu2du_ue_mapping != NULL);
   uint64_t key = ue_id;
   if (hashtable_is_key_exists(cu2du_ue_mapping, key) == HASH_TABLE_OK) {
-    pthread_mutex_unlock(&cu2du_mutex);
-    return false;
+    hashtable_rc_t ret = hashtable_remove(cu2du_ue_mapping, key);
+    DevAssert(ret == HASH_TABLE_OK);
   }
   bool ret = add_hashtable_data(cu2du_ue_mapping, key, data);
   pthread_mutex_unlock(&cu2du_mutex);
@@ -116,14 +116,14 @@ void du_init_f1_ue_data(void)
   pthread_mutex_unlock(&du2cu_mutex);
 }
 
-bool du_add_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data)
+bool du_addmod_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data)
 {
   pthread_mutex_lock(&du2cu_mutex);
   DevAssert(du2cu_ue_mapping != NULL);
   uint64_t key = ue_id;
   if (hashtable_is_key_exists(du2cu_ue_mapping, key) == HASH_TABLE_OK) {
-    pthread_mutex_unlock(&du2cu_mutex);
-    return false;
+    hashtable_rc_t ret = hashtable_remove(du2cu_ue_mapping, key);
+    DevAssert(ret == HASH_TABLE_OK);
   }
   bool ret = add_hashtable_data(du2cu_ue_mapping, key, data);
   pthread_mutex_unlock(&du2cu_mutex);
diff --git a/openair2/F1AP/f1ap_ids.h b/openair2/F1AP/f1ap_ids.h
index 54d17243c5..0847816124 100644
--- a/openair2/F1AP/f1ap_ids.h
+++ b/openair2/F1AP/f1ap_ids.h
@@ -38,13 +38,13 @@ typedef struct f1_ue_data_t {
 } f1_ue_data_t;
 
 void cu_init_f1_ue_data(void);
-bool cu_add_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data);
+bool cu_addmod_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data);
 bool cu_exists_f1_ue_data(uint32_t ue_id);
 f1_ue_data_t cu_get_f1_ue_data(uint32_t ue_id);
 bool cu_remove_f1_ue_data(uint32_t ue_id);
 
 void du_init_f1_ue_data(void);
-bool du_add_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data);
+bool du_addmod_f1_ue_data(uint32_t ue_id, const f1_ue_data_t *data);
 bool du_exists_f1_ue_data(uint32_t ue_id);
 f1_ue_data_t du_get_f1_ue_data(uint32_t ue_id);
 bool du_remove_f1_ue_data(uint32_t ue_id);
diff --git a/openair2/F1AP/f1ap_ids_test.c b/openair2/F1AP/f1ap_ids_test.c
index 8c1860a946..47e85ba777 100644
--- a/openair2/F1AP/f1ap_ids_test.c
+++ b/openair2/F1AP/f1ap_ids_test.c
@@ -30,10 +30,11 @@ void du_data_test()
   du_init_f1_ue_data();
   int rnti = 13;
   f1_ue_data_t data = {.secondary_ue = 1};
-  bool ret = du_add_f1_ue_data(rnti, &data);
+  bool ret = du_addmod_f1_ue_data(rnti, &data);
+  DevAssert(ret);
+  // we can overwrite, no problem
+  ret = du_addmod_f1_ue_data(rnti, &data);
   DevAssert(ret);
-  ret = du_add_f1_ue_data(rnti, &data);
-  DevAssert(!ret);
   bool exists = du_exists_f1_ue_data(rnti);
   DevAssert(exists);
   f1_ue_data_t rdata = du_get_f1_ue_data(rnti);
@@ -45,14 +46,25 @@ void cu_data_test()
   cu_init_f1_ue_data();
   int ue_id = 13;
   f1_ue_data_t data = {.secondary_ue = 1};
-  bool ret = cu_add_f1_ue_data(ue_id, &data);
+  bool ret = cu_addmod_f1_ue_data(ue_id, &data);
+  DevAssert(ret);
+  // we can overwrite, no problem
+  data.secondary_ue = 2;
+  ret = cu_addmod_f1_ue_data(ue_id, &data);
   DevAssert(ret);
-  ret = cu_add_f1_ue_data(ue_id, &data);
-  DevAssert(!ret);
   bool exists = cu_exists_f1_ue_data(ue_id);
   DevAssert(exists);
   f1_ue_data_t rdata = cu_get_f1_ue_data(ue_id);
   DevAssert(rdata.secondary_ue == data.secondary_ue);
+
+  rdata.secondary_ue = 3;
+  // overwrite once more
+  ret = cu_addmod_f1_ue_data(ue_id, &rdata);
+  DevAssert(ret);
+  exists = cu_exists_f1_ue_data(ue_id);
+  DevAssert(exists);
+  f1_ue_data_t r2data = cu_get_f1_ue_data(ue_id);
+  DevAssert(r2data.secondary_ue == rdata.secondary_ue);
 }
 
 int main()
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
index 9c6f5f4b27..4e185e0223 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
@@ -482,7 +482,7 @@ static NR_UE_info_t *create_new_UE(gNB_MAC_INST *mac, uint32_t cu_id)
     return NULL;
 
   f1_ue_data_t new_ue_data = {.secondary_ue = cu_id};
-  du_add_f1_ue_data(rnti, &new_ue_data);
+  du_addmod_f1_ue_data(rnti, &new_ue_data);
 
   const NR_ServingCellConfigCommon_t *scc = mac->common_channels[CC_id].ServingCellConfigCommon;
   const NR_ServingCellConfig_t *sccd = mac->common_channels[CC_id].pre_ServingCellConfig;
@@ -826,7 +826,7 @@ void dl_rrc_message_transfer(const f1ap_dl_rrc_message_t *dl_rrc)
   if (!du_exists_f1_ue_data(dl_rrc->gNB_DU_ue_id)) {
     LOG_D(NR_MAC, "No CU UE ID stored for UE RNTI %04x, adding CU UE ID %d\n", dl_rrc->gNB_DU_ue_id, dl_rrc->gNB_CU_ue_id);
     f1_ue_data_t new_ue_data = {.secondary_ue = dl_rrc->gNB_CU_ue_id};
-    du_add_f1_ue_data(dl_rrc->gNB_DU_ue_id, &new_ue_data);
+    du_addmod_f1_ue_data(dl_rrc->gNB_DU_ue_id, &new_ue_data);
   }
 
   if (UE->expect_reconfiguration && dl_rrc->srb_id == 1) {
diff --git a/openair2/LAYER2/nr_pdcp/cucp_cuup_handler.c b/openair2/LAYER2/nr_pdcp/cucp_cuup_handler.c
index 1d3394e788..8a7ca4c278 100644
--- a/openair2/LAYER2/nr_pdcp/cucp_cuup_handler.c
+++ b/openair2/LAYER2/nr_pdcp/cucp_cuup_handler.c
@@ -150,7 +150,7 @@ void e1_bearer_context_setup(const e1ap_bearer_setup_req_t *req)
   uint32_t cu_up_ue_id = req->gNB_cu_cp_ue_id;
   f1_ue_data_t ued = {.secondary_ue = req->gNB_cu_cp_ue_id};
   if (need_ue_id_mgmt) {
-    cu_add_f1_ue_data(cu_up_ue_id, &ued);
+    cu_addmod_f1_ue_data(cu_up_ue_id, &ued);
     LOG_I(E1AP, "adding UE with CU-CP UE ID %d and CU-UP UE ID %d\n", req->gNB_cu_cp_ue_id, cu_up_ue_id);
   }
 
diff --git a/openair2/RRC/NR/rrc_gNB.c b/openair2/RRC/NR/rrc_gNB.c
index 2456a851de..efe4a53a13 100644
--- a/openair2/RRC/NR/rrc_gNB.c
+++ b/openair2/RRC/NR/rrc_gNB.c
@@ -1181,8 +1181,7 @@ static void rrc_handle_RRCReestablishmentRequest(gNB_RRC_INST *rrc,
     /* update to old DU assoc id -- RNTI + secondary DU UE ID further below */
     f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
     ue_data.du_assoc_id = source_ctx->du->assoc_id;
-    cu_remove_f1_ue_data(UE->rrc_ue_id);
-    cu_add_f1_ue_data(UE->rrc_ue_id, &ue_data);
+    cu_addmod_f1_ue_data(UE->rrc_ue_id, &ue_data);
     nr_rrc_finalize_ho(UE);
   } else if (physCellId != cell_info->nr_pci) {
     /* UE was moving from previous cell so quickly that RRCReestablishment for previous cell was received in this cell */
@@ -1212,8 +1211,7 @@ static void rrc_handle_RRCReestablishmentRequest(gNB_RRC_INST *rrc,
   UE->nr_cellid = msg->nr_cellid;
   f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
   ue_data.secondary_ue = msg->gNB_DU_ue_id;
-  cu_remove_f1_ue_data(UE->rrc_ue_id);
-  cu_add_f1_ue_data(UE->rrc_ue_id, &ue_data);
+  cu_addmod_f1_ue_data(UE->rrc_ue_id, &ue_data);
 
   rrc_gNB_generate_RRCReestablishment(ue_context_p, msg->du2cu_rrc_container, old_rnti, du);
   return;
@@ -2125,8 +2123,7 @@ static void rrc_CU_process_ue_context_modification_response(MessageDef *msg_p, i
     f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
     ue_data.secondary_ue = target_ctx->du_ue_id;
     ue_data.du_assoc_id = target_ctx->du->assoc_id;
-    cu_remove_f1_ue_data(UE->rrc_ue_id);
-    cu_add_f1_ue_data(UE->rrc_ue_id, &ue_data);
+    cu_addmod_f1_ue_data(UE->rrc_ue_id, &ue_data);
     LOG_I(NR_RRC, "UE %d handover: update RNTI from %04x to %04x\n", UE->rrc_ue_id, UE->rnti, target_ctx->new_rnti);
     nr_ho_source_cu_t *source_ctx = UE->ho_context->source;
     DevAssert(source_ctx->old_rnti == UE->rnti);
diff --git a/openair2/RRC/NR/rrc_gNB_UE_context.c b/openair2/RRC/NR/rrc_gNB_UE_context.c
index eae5c0706e..5f3ac385c9 100644
--- a/openair2/RRC/NR/rrc_gNB_UE_context.c
+++ b/openair2/RRC/NR/rrc_gNB_UE_context.c
@@ -204,7 +204,7 @@ rrc_gNB_ue_context_t *rrc_gNB_create_ue_context(sctp_assoc_t assoc_id,
   AssertFatal(!cu_exists_f1_ue_data(ue->rrc_ue_id),
               "UE F1 Context for ID %d already exists, logic bug\n",
               ue->rrc_ue_id);
-  cu_add_f1_ue_data(ue->rrc_ue_id, &ue_data);
+  cu_addmod_f1_ue_data(ue->rrc_ue_id, &ue_data);
 
   RB_INSERT(rrc_nr_ue_tree_s, &rrc_instance_pP->rrc_ue_head, ue_context_p);
   LOG_UE_EVENT(ue,
diff --git a/openair2/RRC/NR/rrc_gNB_cuup.c b/openair2/RRC/NR/rrc_gNB_cuup.c
index 621ebca56e..f6fb8750a3 100644
--- a/openair2/RRC/NR/rrc_gNB_cuup.c
+++ b/openair2/RRC/NR/rrc_gNB_cuup.c
@@ -132,8 +132,7 @@ sctp_assoc_t get_new_cuup_for_ue(const gNB_RRC_INST *rrc, const gNB_RRC_UE_t *ue
 
   /* update the association for the UE so it will be picked up later */
   ue_data.e1_assoc_id = selected->assoc_id;
-  cu_remove_f1_ue_data(ue->rrc_ue_id);
-  cu_add_f1_ue_data(ue->rrc_ue_id, &ue_data);
+  cu_addmod_f1_ue_data(ue->rrc_ue_id, &ue_data);
   LOG_I(RRC, "UE %d associating to CU-UP assoc_id %d out of %ld CU-UPs\n", ue->rrc_ue_id, ue_data.e1_assoc_id, rrc->num_cuups);
 
   return ue_data.e1_assoc_id;
diff --git a/openair2/RRC/NR/rrc_gNB_du.c b/openair2/RRC/NR/rrc_gNB_du.c
index 654ef04be1..8900d183b4 100644
--- a/openair2/RRC/NR/rrc_gNB_du.c
+++ b/openair2/RRC/NR/rrc_gNB_du.c
@@ -426,9 +426,8 @@ static int invalidate_du_connections(gNB_RRC_INST *rrc, sctp_assoc_t assoc_id)
     if (ue_data.du_assoc_id == assoc_id) {
       /* this UE belongs to the DU that disconnected, set du_assoc_id to 0,
        * meaning DU is offline, then trigger release request */
-      cu_remove_f1_ue_data(ue_id);
       ue_data.du_assoc_id = 0;
-      cu_add_f1_ue_data(ue_id, &ue_data);
+      cu_addmod_f1_ue_data(ue_id, &ue_data);
       rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_REQ(0,
                                                ue_context_p,
                                                NGAP_CAUSE_RADIO_NETWORK,
diff --git a/openair2/RRC/NR/rrc_gNB_nsa.c b/openair2/RRC/NR/rrc_gNB_nsa.c
index bae7c45180..515776f2a1 100644
--- a/openair2/RRC/NR/rrc_gNB_nsa.c
+++ b/openair2/RRC/NR/rrc_gNB_nsa.c
@@ -355,9 +355,9 @@ void rrc_add_nsa_user(gNB_RRC_INST *rrc, rrc_gNB_ue_context_t *ue_context_p, x2a
   uint32_t du_ue_id = ue_context_p->ue_context.rnti;
   uint32_t rrc_ue_id = ue_context_p->ue_context.rrc_ue_id;
   f1_ue_data_t du_ue_data = {.secondary_ue = rrc_ue_id};
-  du_add_f1_ue_data(du_ue_id, &du_ue_data);
+  du_addmod_f1_ue_data(du_ue_id, &du_ue_data);
   f1_ue_data_t cu_ue_data = {.secondary_ue = du_ue_id};
-  cu_add_f1_ue_data(rrc_ue_id, &cu_ue_data);
+  cu_addmod_f1_ue_data(rrc_ue_id, &cu_ue_data);
   LOG_I(RRC, "Assign CU UE ID %d and DU UE ID %d to UE RNTI %04x\n", rrc_ue_id, du_ue_id, ue_context_p->ue_context.rnti);
 
   // configure MAC and RLC