diff --git a/tests/bsim/bluetooth/audio/overlay-bt_ll_sw_split.conf b/tests/bsim/bluetooth/audio/overlay-bt_ll_sw_split.conf
index ea37e1be3ed..cf40449c4cc 100644
--- a/tests/bsim/bluetooth/audio/overlay-bt_ll_sw_split.conf
+++ b/tests/bsim/bluetooth/audio/overlay-bt_ll_sw_split.conf
@@ -77,7 +77,7 @@ CONFIG_BT_CTLR_CONN_ISO_LOW_LATENCY_POLICY=y
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
-CONFIG_BT_CTLR_ISO_TX_BUFFERS=8
+CONFIG_BT_CTLR_ISO_TX_BUFFERS=18
 CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 
 # ISO Receptions
diff --git a/tests/bsim/bluetooth/audio/overlay-nrf5340_cpunet_iso-bt_ll_sw_split.conf b/tests/bsim/bluetooth/audio/overlay-nrf5340_cpunet_iso-bt_ll_sw_split.conf
new file mode 100644
index 00000000000..4e61f830892
--- /dev/null
+++ b/tests/bsim/bluetooth/audio/overlay-nrf5340_cpunet_iso-bt_ll_sw_split.conf
@@ -0,0 +1,7 @@
+# In theory, CONFIG_BT_ISO_TX_BUF_COUNT=1, should be sufficient but this count
+# is used in the context of IPC which falls into a "Newton's Cradle" effect
+# where probably (CONFIG_BT_CTLR_ISO_TX_BUFFERS - CONFIG_BT_ISO_TX_BUF_COUNT)
+# buffers get throttled. Hence, always have the value equal or greater.
+CONFIG_BT_ISO_TX_BUF_COUNT=18
+
+CONFIG_BT_CTLR_ISO_TX_BUFFERS=18
diff --git a/tests/bsim/bluetooth/audio/prj.conf b/tests/bsim/bluetooth/audio/prj.conf
index 4879749ef78..16d251e7e8b 100644
--- a/tests/bsim/bluetooth/audio/prj.conf
+++ b/tests/bsim/bluetooth/audio/prj.conf
@@ -51,7 +51,7 @@ CONFIG_BT_BAP_BROADCAST_SNK_STREAM_COUNT=2
 CONFIG_BT_ISO_PERIPHERAL=y
 CONFIG_BT_ISO_MAX_CHAN=4
 CONFIG_BT_ISO_TX_MTU=310
-CONFIG_BT_ISO_TX_BUF_COUNT=4
+CONFIG_BT_ISO_TX_BUF_COUNT=36
 CONFIG_BT_ISO_RX_MTU=310
 CONFIG_BT_ISO_RX_BUF_COUNT=4
 
diff --git a/tests/bsim/bluetooth/audio/src/cap_acceptor_test.c b/tests/bsim/bluetooth/audio/src/cap_acceptor_test.c
index a90e090789c..4a4cc6a22c1 100644
--- a/tests/bsim/bluetooth/audio/src/cap_acceptor_test.c
+++ b/tests/bsim/bluetooth/audio/src/cap_acceptor_test.c
@@ -39,6 +39,17 @@
 #include "bap_common.h"
 
 #if defined(CONFIG_BT_CAP_ACCEPTOR)
+/* Zephyr Controller works best while Extended Advertising interval to be a multiple
+ * of the ISO Interval minus 10 ms (max. advertising random delay). This is
+ * required to place the AUX_ADV_IND PDUs in a non-overlapping interval with the
+ * Broadcast ISO radio events.
+ */
+#define BT_LE_EXT_ADV_CONN_CUSTOM \
+		BT_LE_ADV_PARAM(BT_LE_ADV_OPT_EXT_ADV | BT_LE_ADV_OPT_CONN, \
+				BT_GAP_MS_TO_ADV_INTERVAL(140), \
+				BT_GAP_MS_TO_ADV_INTERVAL(140), \
+				NULL)
+
 extern enum bst_result_t bst_result;
 
 #define SINK_CONTEXT                                                                               \
@@ -608,7 +619,7 @@ void test_start_adv(void)
 	struct bt_le_ext_adv *ext_adv;
 
 	/* Create a connectable non-scannable advertising set */
-	err = bt_le_ext_adv_create(BT_LE_ADV_CONN_FAST_1, NULL, &ext_adv);
+	err = bt_le_ext_adv_create(BT_LE_EXT_ADV_CONN_CUSTOM, NULL, &ext_adv);
 	if (err != 0) {
 		FAIL("Failed to create advertising set (err %d)\n", err);
 
diff --git a/tests/bsim/bluetooth/audio/src/cap_commander_test.c b/tests/bsim/bluetooth/audio/src/cap_commander_test.c
index 0b2c1f48ab6..cbd91fe265d 100644
--- a/tests/bsim/bluetooth/audio/src/cap_commander_test.c
+++ b/tests/bsim/bluetooth/audio/src/cap_commander_test.c
@@ -311,7 +311,7 @@ static bool scan_check_and_sync_broadcast(struct bt_data *data, void *user_data)
 
 	printk("Found broadcaster with ID 0x%06X and addr %s and sid 0x%02X\n", broadcast_id,
 	       le_addr, info->sid);
-	printk("Adv type %02X interval %u", info->adv_type, info->interval);
+	printk("Adv type %02X interval %u\n", info->adv_type, info->interval);
 
 	SET_FLAG(flag_broadcaster_found);
 
diff --git a/tests/bsim/bluetooth/audio/src/cap_initiator_broadcast_test.c b/tests/bsim/bluetooth/audio/src/cap_initiator_broadcast_test.c
index 98896e40766..ea6eacef4fb 100644
--- a/tests/bsim/bluetooth/audio/src/cap_initiator_broadcast_test.c
+++ b/tests/bsim/bluetooth/audio/src/cap_initiator_broadcast_test.c
@@ -39,15 +39,15 @@
  * Broadcast ISO radio events.
  */
 #define BT_LE_EXT_ADV_CUSTOM                                                                       \
-	BT_LE_ADV_PARAM(BT_LE_ADV_OPT_EXT_ADV, BT_GAP_MS_TO_ADV_INTERVAL(80),                      \
-			BT_GAP_MS_TO_ADV_INTERVAL(80), NULL)
+	BT_LE_ADV_PARAM(BT_LE_ADV_OPT_EXT_ADV, BT_GAP_MS_TO_ADV_INTERVAL(140),                     \
+			BT_GAP_MS_TO_ADV_INTERVAL(140), NULL)
 
 #define BT_LE_PER_ADV_CUSTOM                                                                       \
-	BT_LE_PER_ADV_PARAM(BT_GAP_MS_TO_PER_ADV_INTERVAL(90), BT_GAP_MS_TO_PER_ADV_INTERVAL(90),  \
-			    BT_LE_PER_ADV_OPT_NONE)
+	BT_LE_PER_ADV_PARAM(BT_GAP_MS_TO_PER_ADV_INTERVAL(150),                                    \
+			    BT_GAP_MS_TO_PER_ADV_INTERVAL(150), BT_LE_PER_ADV_OPT_NONE)
 
 #define BROADCAST_STREMT_CNT    CONFIG_BT_BAP_BROADCAST_SRC_STREAM_COUNT
-#define BROADCAST_ENQUEUE_COUNT 2U
+#define BROADCAST_ENQUEUE_COUNT 18U
 #define TOTAL_BUF_NEEDED        (BROADCAST_ENQUEUE_COUNT * BROADCAST_STREMT_CNT)
 #define CAP_AC_MAX_STREAM       2
 #define LOCATION                (BT_AUDIO_LOCATION_FRONT_LEFT | BT_AUDIO_LOCATION_FRONT_RIGHT)
diff --git a/tests/bsim/bluetooth/audio/sysbuild.cmake b/tests/bsim/bluetooth/audio/sysbuild.cmake
index 1b8d10c8db3..5dfd594349c 100644
--- a/tests/bsim/bluetooth/audio/sysbuild.cmake
+++ b/tests/bsim/bluetooth/audio/sysbuild.cmake
@@ -18,6 +18,11 @@ if(SB_CONFIG_NET_CORE_IMAGE_HCI_IPC)
 	 CACHE INTERNAL ""
 	)
 
+	set(${NET_APP}_EXTRA_CONF_FILE
+	 ${APP_DIR}/overlay-nrf5340_cpunet_iso-bt_ll_sw_split.conf
+	 CACHE INTERNAL ""
+	)
+
 	native_simulator_set_child_images(${DEFAULT_IMAGE} ${NET_APP})
 endif()
 
diff --git a/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_12.sh b/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_12.sh
index 607d6837699..b7fc2721d62 100755
--- a/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_12.sh
+++ b/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_12.sh
@@ -51,19 +51,19 @@ Execute_AC_12 48_5_1
 Execute_AC_12 48_6_1
 
 # High reliability
-# Execute_AC_12 8_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 8_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 16_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 16_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 24_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 24_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 32_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 32_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 441_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 441_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 48_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 48_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 48_3_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 48_4_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 48_5_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_12 48_6_2 # BT_ISO_FLAGS_ERROR
+Execute_AC_12 8_1_2
+Execute_AC_12 8_2_2
+Execute_AC_12 16_1_2
+Execute_AC_12 16_2_2
+Execute_AC_12 24_1_2
+Execute_AC_12 24_2_2
+Execute_AC_12 32_1_2
+Execute_AC_12 32_2_2
+# Execute_AC_12 441_1_2 # BT_ISO_FLAGS_LOST
+# Execute_AC_12 441_2_2 # BT_ISO_FLAGS_LOST
+Execute_AC_12 48_1_2
+Execute_AC_12 48_2_2
+Execute_AC_12 48_3_2
+Execute_AC_12 48_4_2
+Execute_AC_12 48_5_2
+Execute_AC_12 48_6_2
diff --git a/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_14.sh b/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_14.sh
index 0ac6ed685fb..1b5484a42ac 100755
--- a/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_14.sh
+++ b/tests/bsim/bluetooth/audio/test_scripts/cap_broadcast_ac_14.sh
@@ -41,9 +41,7 @@ Execute_AC_14 24_1_1
 Execute_AC_14 24_2_1
 Execute_AC_14 32_1_1
 Execute_AC_14 32_2_1
-# ASSERTION FAIL [err == ((isoal_status_t) 0x00) || err == ((isoal_status_t) 0x04)]
-# @ WEST_TOPDIR/zephyr/subsys/bluetooth/controller/hci/hci_driver.c:513
-# Execute_AC_14 441_1_1
+Execute_AC_14 441_1_1
 # ASSERTION FAIL [err == ((isoal_status_t) 0x00) || err == ((isoal_status_t) 0x04)]
 # @ WEST_TOPDIR/zephyr/subsys/bluetooth/controller/hci/hci_driver.c:513
 # Execute_AC_14 441_2_1
@@ -55,19 +53,19 @@ Execute_AC_14 48_5_1
 Execute_AC_14 48_6_1
 
 # High reliability
-# Execute_AC_14 8_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 8_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 16_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 16_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 24_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 24_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 32_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 32_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 441_1_2 # BT_ISO_FLAGS_ERROR
+Execute_AC_14 8_1_2
+Execute_AC_14 8_2_2
+Execute_AC_14 16_1_2
+Execute_AC_14 16_2_2
+Execute_AC_14 24_1_2
+Execute_AC_14 24_2_2
+Execute_AC_14 32_1_2
+Execute_AC_14 32_2_2
+# Execute_AC_14 441_1_2 # BT_ISO_FLAGS_LOST
 # Execute_AC_14 441_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 48_1_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 48_2_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 48_3_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 48_4_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 48_5_2 # BT_ISO_FLAGS_ERROR
-# Execute_AC_14 48_6_2 # BT_ISO_FLAGS_ERROR
+Execute_AC_14 48_1_2
+Execute_AC_14 48_2_2
+Execute_AC_14 48_3_2
+Execute_AC_14 48_4_2
+# Execute_AC_14 48_5_2  # BT_ISO_FLAGS_ERROR
+# Execute_AC_14 48_6_2  # BT_ISO_FLAGS_ERROR