In NDB clustering one sql node is successfully connected but another is not.

[Mahadi Hasan Joy]

I have configured all the data and management nodes well. I have two SQL nodes. One is connected well, but another is not. I have checked my log file. It's like:
"
2021-09-23 12:18:19 [MgmtSrvr] INFO -- Alloc node id 6 succeeded
2021-09-23 12:18:19 [MgmtSrvr] INFO -- Nodeid 6 allocated for API at 192.168.7.135
2021-09-23 12:18:19 [MgmtSrvr] INFO -- Node 6: mysqld --server-id=1
2021-09-23 12:18:40 [MgmtSrvr] WARNING -- Node 3: Releasing node id allocation for node 6
"

There is no firewall between any server, all firewalls are disabled. I have tried different server, but only one server is capable to connect as sql node.

my management config:
"
[ndb_mgmd default]
PortNumber=1186
# Directory for MGM node log files
DataDir=/var/lib/mysql-cluster

[ndb_mgmd]
NodeId=1
HostName=192.168.7.130

[ndb_mgmd]
NodeId=2
HostName=192.168.7.134

[ndbd default]
NoOfReplicas=2
DataMemory=256M
IndexMemory=128M
DataDir=/var/lib/mysql-cluster

[ndbd]
NodeId=3
HostName=192.168.7.132

[ndbd]
NodeId=4
HostName=192.168.7.133

[mysqld]
NodeId =5
HostName=192.168.7.134

[mysqld]
NodeId =6
HostName=192.168.7.135
"
[mysqld]
ndbcluster
ndb-connectstring=192.168.7.130,192.168.7.134

[mysql_cluster]
ndb-connectstring=192.168.7.130,192.168.7.134

"

My sql node config:
"
[mysqld]
ndbcluster
ndb-connectstring=192.168.7.130,192.168.7.134
default_storage_engine=ndbcluster

[mysql_cluster]
ndb-connectstring=192.168.7.130,192.168.7.134
"

I have checked all the thing, but still struglling to connect sql node. Here is my result cluster config:

"
Cluster Configuration
---------------------
[ndbd(NDB)] 2 node(s)
id=3 @192.168.7.132 (mysql-8.0.21 ndb-8.0.21, Nodegroup: 0, *)
id=4 @192.168.7.133 (mysql-8.0.21 ndb-8.0.21, Nodegroup: 0)

[ndb_mgmd(MGM)] 2 node(s)
id=1 @192.168.7.130 (mysql-8.0.21 ndb-8.0.21)
id=2 @192.168.7.134 (mysql-8.0.21 ndb-8.0.21)

[mysqld(API)] 2 node(s)
id=5 @192.168.7.134 (mysql-8.0.21 ndb-8.0.21)
id=6 (not connected, accepting connect from 192.168.7.135)

"

My mySql-ndb cluster version:
mysql Ver 8.0.21-cluster for Linux on x86_64 (MySQL Cluster Community Server - GPL)


Thanks in advance!