diff --git a/samples/mcumgr/ble_mcumgr/prj.conf b/samples/mcumgr/ble_mcumgr/prj.conf
index 6cc933cb07..26b3cb59c3 100644
--- a/samples/mcumgr/ble_mcumgr/prj.conf
+++ b/samples/mcumgr/ble_mcumgr/prj.conf
@@ -10,12 +10,12 @@ CONFIG_BLE_CONN_PARAMS=y
 # MCUmgr requires storage of a vendor UUID
 CONFIG_NRF_SDH_BLE_VS_UUID_COUNT=2
 
-CONFIG_BLE_CONN_PARAMS_MAX_CONN_INTERVAL=256
+CONFIG_BLE_CONN_PARAMS_MAX_CONN_INTERVAL=9
 CONFIG_BLE_CONN_PARAMS_INITIATE_ATT_MTU_EXCHANGE=y
-CONFIG_BLE_CONN_PARAMS_DATA_LENGTH_RX=251
-CONFIG_BLE_CONN_PARAMS_DATA_LENGTH_TX=251
+CONFIG_BLE_CONN_PARAMS_DATA_LENGTH_RX=247
+CONFIG_BLE_CONN_PARAMS_DATA_LENGTH_TX=247
 CONFIG_BLE_CONN_PARAMS_INITIATE_DATA_LENGTH_UPDATE=y
-CONFIG_NRF_SDH_BLE_GAP_EVENT_LENGTH=10
+CONFIG_NRF_SDH_BLE_GAP_EVENT_LENGTH=800
 
 CONFIG_ZCBOR=y
 CONFIG_NET_BUF=y
diff --git a/samples/mcumgr/ble_mcumgr/socs/nrf54l05_cpuapp_s115_softdevice_mcuboot.conf b/samples/mcumgr/ble_mcumgr/socs/nrf54l05_cpuapp_s115_softdevice_mcuboot.conf
index edb790a441..5d96537f2d 100644
--- a/samples/mcumgr/ble_mcumgr/socs/nrf54l05_cpuapp_s115_softdevice_mcuboot.conf
+++ b/samples/mcumgr/ble_mcumgr/socs/nrf54l05_cpuapp_s115_softdevice_mcuboot.conf
@@ -1,4 +1,3 @@
-CONFIG_NRF_SDH_BLE_GATT_MAX_MTU_SIZE=498
-CONFIG_BLE_CONN_PARAMS_MAX_CONN_INTERVAL=24
-CONFIG_BLE_CONN_PARAMS_SUP_TIMEOUT=20
+CONFIG_NRF_SDH_BLE_GATT_MAX_MTU_SIZE=251
+CONFIG_BLE_CONN_PARAMS_SUP_TIMEOUT=42
 CONFIG_BLE_CONN_PARAMS_MAX_SUP_TIMEOUT_DEVIATION=20
diff --git a/samples/mcumgr/ble_mcumgr/socs/nrf54l10_cpuapp_s115_softdevice_mcuboot.conf b/samples/mcumgr/ble_mcumgr/socs/nrf54l10_cpuapp_s115_softdevice_mcuboot.conf
index edb790a441..5d96537f2d 100644
--- a/samples/mcumgr/ble_mcumgr/socs/nrf54l10_cpuapp_s115_softdevice_mcuboot.conf
+++ b/samples/mcumgr/ble_mcumgr/socs/nrf54l10_cpuapp_s115_softdevice_mcuboot.conf
@@ -1,4 +1,3 @@
-CONFIG_NRF_SDH_BLE_GATT_MAX_MTU_SIZE=498
-CONFIG_BLE_CONN_PARAMS_MAX_CONN_INTERVAL=24
-CONFIG_BLE_CONN_PARAMS_SUP_TIMEOUT=20
+CONFIG_NRF_SDH_BLE_GATT_MAX_MTU_SIZE=251
+CONFIG_BLE_CONN_PARAMS_SUP_TIMEOUT=42
 CONFIG_BLE_CONN_PARAMS_MAX_SUP_TIMEOUT_DEVIATION=20
diff --git a/samples/mcumgr/ble_mcumgr/socs/nrf54l15_cpuapp_s115_softdevice_mcuboot.conf b/samples/mcumgr/ble_mcumgr/socs/nrf54l15_cpuapp_s115_softdevice_mcuboot.conf
index edb790a441..5d96537f2d 100644
--- a/samples/mcumgr/ble_mcumgr/socs/nrf54l15_cpuapp_s115_softdevice_mcuboot.conf
+++ b/samples/mcumgr/ble_mcumgr/socs/nrf54l15_cpuapp_s115_softdevice_mcuboot.conf
@@ -1,4 +1,3 @@
-CONFIG_NRF_SDH_BLE_GATT_MAX_MTU_SIZE=498
-CONFIG_BLE_CONN_PARAMS_MAX_CONN_INTERVAL=24
-CONFIG_BLE_CONN_PARAMS_SUP_TIMEOUT=20
+CONFIG_NRF_SDH_BLE_GATT_MAX_MTU_SIZE=251
+CONFIG_BLE_CONN_PARAMS_SUP_TIMEOUT=42
 CONFIG_BLE_CONN_PARAMS_MAX_SUP_TIMEOUT_DEVIATION=20