diff --git a/openair1/SIMULATION/NR_PHY/dlsim.c b/openair1/SIMULATION/NR_PHY/dlsim.c
index c4efb2752e..b713fe5f5f 100644
--- a/openair1/SIMULATION/NR_PHY/dlsim.c
+++ b/openair1/SIMULATION/NR_PHY/dlsim.c
@@ -804,7 +804,7 @@ printf("%d\n", slot);
   rnti_t rnti = 0x1234;
   int uid = 0;
   NR_CellGroupConfig_t *secondaryCellGroup = get_default_secondaryCellGroup(scc, UE_Capability_nr, 0, 1, &conf, uid);
-  secondaryCellGroup->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(rnti, uid, scc);
+  secondaryCellGroup->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(rnti, uid, scc, frame);
 
   /* -U option modify DMRS */
   if(modify_dmrs) {
diff --git a/openair1/SIMULATION/NR_PHY/ulsim.c b/openair1/SIMULATION/NR_PHY/ulsim.c
index 0d3687bb4d..ec4a7190fa 100644
--- a/openair1/SIMULATION/NR_PHY/ulsim.c
+++ b/openair1/SIMULATION/NR_PHY/ulsim.c
@@ -708,7 +708,7 @@ int main(int argc, char *argv[])
   rnti_t rnti = 0x1234;
   int uid = 0;
   NR_CellGroupConfig_t *secondaryCellGroup = get_default_secondaryCellGroup(scc, UE_Capability_nr, 0, 1, &conf, uid);
-  secondaryCellGroup->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(rnti, uid, scc);
+  secondaryCellGroup->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(rnti, uid, scc, frame);
 
   NR_BCCH_BCH_Message_t *mib = get_new_MIB_NR(scc);
 
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 f73f4b8f70..b3d596b524 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
@@ -572,11 +572,11 @@ static NR_UE_info_t *create_new_UE(gNB_MAC_INST *mac, uint32_t cu_id, const NR_C
   const nr_mac_config_t *configuration = &mac->radio_config;
   if (is_SA) {
     cellGroupConfig = get_initial_cellGroupConfig(UE->uid, scc, &mac->radio_config, &mac->rlc_config);
-    cellGroupConfig->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(UE->rnti, UE->uid, scc);
+    cellGroupConfig->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(UE->rnti, UE->uid, scc, mac->frame);
   } else {
     NR_UE_NR_Capability_t *cap = get_ue_nr_cap_from_cg_config_info(cgci);
     cellGroupConfig = get_default_secondaryCellGroup(scc, cap, 1, 1, configuration, UE->uid);
-    cellGroupConfig->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(UE->rnti, UE->uid, scc);
+    cellGroupConfig->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(UE->rnti, UE->uid, scc, mac->frame);
     // TODO: in NSA we assign capabilities here, otherwise outside => not logic
     UE->capability = cap;
   }
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c
index bb108d4004..197c5d54b9 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c
@@ -4123,7 +4123,7 @@ NR_CellGroupConfig_t *get_default_secondaryCellGroup(const NR_ServingCellConfigC
   return secondaryCellGroup;
 }
 
-NR_ReconfigurationWithSync_t *get_reconfiguration_with_sync(rnti_t rnti, uid_t uid, const NR_ServingCellConfigCommon_t *scc)
+NR_ReconfigurationWithSync_t *get_reconfiguration_with_sync(rnti_t rnti, uid_t uid, const NR_ServingCellConfigCommon_t *scc, int frame)
 {
   NR_ReconfigurationWithSync_t *reconfigurationWithSync = calloc(1, sizeof(*reconfigurationWithSync));
   reconfigurationWithSync->newUE_Identity = rnti;
@@ -4133,6 +4133,19 @@ NR_ReconfigurationWithSync_t *get_reconfiguration_with_sync(rnti_t rnti, uid_t u
 
   reconfigurationWithSync->spCellConfigCommon = clone_ServingCellConfigCommon(scc);
 
+  // in case of ReconfigurationWithSync, the epochTime_r17 must be present if there is a ntn_Config_r17
+  if (reconfigurationWithSync->spCellConfigCommon->ext2 && reconfigurationWithSync->spCellConfigCommon->ext2->ntn_Config_r17) {
+    NR_NTN_Config_r17_t *ntncfg = reconfigurationWithSync->spCellConfigCommon->ext2->ntn_Config_r17;
+    if (!ntncfg->epochTime_r17) {
+      ntncfg->epochTime_r17 = calloc(1, sizeof(*ntncfg->epochTime_r17));
+      // the epochTime_r17 is esp. relevant for the timer T430, which runs for multiples of 5 seconds.
+      // here we don't have access to the current subFrame number, so we only set the SFN.
+      // the error of up to 10 ms should be acceptable for this long running timer.
+      ntncfg->epochTime_r17->sfn_r17 = frame;
+      ntncfg->epochTime_r17->subFrameNR_r17 = 0;
+    }
+  }
+
   reconfigurationWithSync->rach_ConfigDedicated = calloc(1, sizeof(*reconfigurationWithSync->rach_ConfigDedicated));
   reconfigurationWithSync->rach_ConfigDedicated->present = NR_ReconfigurationWithSync__rach_ConfigDedicated_PR_uplink;
   NR_RACH_ConfigDedicated_t *uplink = calloc(1, sizeof(*uplink));
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h
index d5df69b3c6..89ce03e7f5 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h
@@ -110,7 +110,7 @@ NR_CellGroupConfig_t *get_default_secondaryCellGroup(const NR_ServingCellConfigC
                                                      const nr_mac_config_t *configuration,
                                                      int uid);
 
-NR_ReconfigurationWithSync_t *get_reconfiguration_with_sync(rnti_t rnti, uid_t uid, const NR_ServingCellConfigCommon_t *scc);
+NR_ReconfigurationWithSync_t *get_reconfiguration_with_sync(rnti_t rnti, uid_t uid, const NR_ServingCellConfigCommon_t *scc, int frame);
 
 NR_RLC_BearerConfig_t *get_SRB_RLC_BearerConfig(long channelId,
                                                 long priority,