Sql-server – High Availability Error 35250 and “An error occurred while receiving data: ‘10054(An existing connection was forcibly closed by the remote host.)

I am facing problem in configuring High Availability, this is my 30-40 time configuration of Always On Availability Groups with central subscriber replication topology and I have never been stuck like this with SQL Server error 35250. I searched a lot but I was unsuccessful in fixing it.

I got this error:

An error occurred while receiving data:
'10054 (An existing connection was forcibly closed by the remote host.)'.

I am using Windows Server 2012 R2 with two node server on SQL Server 2014 (64 bit).

Windows login account and SQL Server service account are both running under a domain account (abc\Administrator).

hadr_endpoint (port-5022) are started with window login permission.

My Always On endpoint ([Hadr_endpoint]) are not blocked by firewall because all firewalls are stopped.

Msg 35250, Level 16, State 7, Line 1
The connection to the primary replica is not active. The command cannot be processed.

Note I am not installed any hotfixes.

I create a domain admin account (on DC) like domainname.in\Administrator and give the all permission to this user (under Member Of tab) and login with domainname\Administrator to the both server. Login in SQL Server with same domainname\Administrator, same service account domainname\Administrator. Note – I created user domainname.in\Administrator but login with domainname\Administrator without '.in'. Is it the issue?

Endpoint URL (please check with ".in" and service account without ".in" (is this the issue?)

My network team not using any kind of network capture and we stopped firewall. We are not using any security software. We are using cyberoam and we also pin all the three server into same switch.

CREATE ENDPOINT [Hadr_endpoint] 
    STATE=STARTED
    AS TCP (LISTENER_PORT = 5022, LISTENER_IP = ALL)
    FOR DATA_MIRRORING (ROLE = ALL, AUTHENTICATION = WINDOWS NEGOTIATE
, ENCRYPTION = REQUIRED ALGORITHM AES)

Service Broker script:

CREATE ENDPOINT [BrokerEndpoint] 
    STATE=STARTED
    AS TCP (LISTENER_PORT = 4022, LISTENER_IP = ALL)
    FOR SERVICE_BROKER (MESSAGE_FORWARDING = ENABLED
, MESSAGE_FORWARD_SIZE = 10
, AUTHENTICATION = WINDOWS NEGOTIATE
, ENCRYPTION = REQUIRED ALGORITHM AES)
GO

I am not using RC4 algorithm for endpoint or service broker. I also increased session timeout time with 60 seconds for secondary replica. I also see the .dag file and it show "failure_condition_level 3". I know probably this is network issue but my network person unable to solve it.

Is there any user mapping issue in SQL Server? Any database is compulsory add to my SQL Server login account?