diff --git a/tests/complex/attach-test.c b/tests/complex/attach-test.c
index 49ac74740..455ad19f4 100644
--- a/tests/complex/attach-test.c
+++ b/tests/complex/attach-test.c
@@ -412,6 +412,8 @@ static void attach_test1(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /* eNB disonncect from MME */
     testenb_s1ap_close(s1ap);
 
@@ -751,6 +753,8 @@ static void attach_test2(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456826"));
     ABTS_PTR_NOTNULL(tc, doc);
     ABTS_TRUE(tc, mongoc_collection_remove(collection, 
@@ -1079,6 +1083,8 @@ static void attach_test3(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456797"));
     ABTS_PTR_NOTNULL(tc, doc);
     ABTS_TRUE(tc, mongoc_collection_remove(collection,
@@ -1260,6 +1266,8 @@ static void attach_test4(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     doc = BCON_NEW("imsi", BCON_UTF8("001010000000002"));
     ABTS_PTR_NOTNULL(tc, doc);
     ABTS_TRUE(tc, mongoc_collection_remove(collection,
@@ -1588,6 +1596,8 @@ static void attach_test5(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456937"));
     ABTS_PTR_NOTNULL(tc, doc);
@@ -1765,6 +1775,8 @@ static void attach_test6(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     doc = BCON_NEW("imsi", BCON_UTF8("001010000000002"));
     ABTS_PTR_NOTNULL(tc, doc);
     ABTS_TRUE(tc, mongoc_collection_remove(collection,
diff --git a/tests/complex/handover-test.c b/tests/complex/handover-test.c
index eaa9b0162..348e388c3 100644
--- a/tests/complex/handover-test.c
+++ b/tests/complex/handover-test.c
@@ -781,6 +781,8 @@ static void handover_test2(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap2, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456815"));
     ABTS_PTR_NOTNULL(tc, doc);
diff --git a/tests/complex/volte-test.c b/tests/complex/volte-test.c
index 295b212e2..a550d5569 100644
--- a/tests/complex/volte-test.c
+++ b/tests/complex/volte-test.c
@@ -291,6 +291,8 @@ static void volte_test1(abts_case *tc, void *data)
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
+    
+    ogs_msleep(200);
 
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456819"));
@@ -519,6 +521,8 @@ static void volte_test2(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
 #if 0 /* TFT Rule Tester */
     /* Send GTP-U ICMP Packet */
 #if 1
diff --git a/tests/csfb/mo-idle-test.c b/tests/csfb/mo-idle-test.c
index 15568a814..3c63be63e 100644
--- a/tests/csfb/mo-idle-test.c
+++ b/tests/csfb/mo-idle-test.c
@@ -329,6 +329,8 @@ static void test1_func(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("262420000118139"));
     ABTS_PTR_NOTNULL(tc, doc);
@@ -517,6 +519,8 @@ static void test2_func(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("262420000118139"));
     ABTS_PTR_NOTNULL(tc, doc);
@@ -784,6 +788,8 @@ static void test3_func(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("262420000118139"));
     ABTS_PTR_NOTNULL(tc, doc);
@@ -961,6 +967,8 @@ static void test4_func(abts_case *tc, void *data)
     ABTS_PTR_NOTNULL(tc, recvbuf);
     ogs_pkbuf_free(recvbuf);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("262420000118139"));
     ABTS_PTR_NOTNULL(tc, doc);
diff --git a/tests/csfb/mt-idle-test.c b/tests/csfb/mt-idle-test.c
index 8c9a5d9a1..192809d56 100644
--- a/tests/csfb/mt-idle-test.c
+++ b/tests/csfb/mt-idle-test.c
@@ -277,6 +277,8 @@ static void test1_func(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("262420000118139"));
     ABTS_PTR_NOTNULL(tc, doc);
diff --git a/tests/volte/volte-test.c b/tests/volte/volte-test.c
index 5c1a387e7..f165b47ed 100644
--- a/tests/volte/volte-test.c
+++ b/tests/volte/volte-test.c
@@ -295,6 +295,8 @@ static void volte_test1(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456819"));
     ABTS_PTR_NOTNULL(tc, doc);
@@ -586,6 +588,8 @@ static void volte_test2(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    ogs_msleep(200);
+
     /********** Remove Subscriber in Database */
     doc = BCON_NEW("imsi", BCON_UTF8("001010123456819"));
     ABTS_PTR_NOTNULL(tc, doc);