Mirroring issue with mirror server

I am running two Windows Servers 2012 R2 with SQL Server 2014 Standard Edition. I have strange issue on mirroring. I configured mirroring on for 15 databases, no Witness server. The Principal server show all database is Principal, Synchronized and the Mirror is Mirror, Synchronized/Restoring. When I open Database Mirror Monitor I see Role Principal is in Mirroring State Synchronized but the Mirror's Role is not connected. I have fail over in both directions and the database came up on the mirror server normally. data is replicating for troubleshooting purpose I have done below steps. 1. I have seen in error log in principle nothing is related to mirroring traced I can see most of the errors in principle are Error: 18456, Severity: 14, State: 38. 2. I have seen errors in mirroring server for all the databases are Database mirroring connection error 4 'An error occurred while receiving data: '10054(An existing connection was forcibly closed by the remote host.)'.' for 'TCP://server.company.com:5022'. Error: 1474, Severity: 16, State: 3. I have tried to resolve by stop and start the endpoint its was not resolved. 4. I have tried pause and resume it is also not resolved. 5. I have verified TCP/IP it is enabled on both the servers. 6. I have tried to configure alias it is also not resolve. 7. I have telnet from each other, it seems have no communication issues 8. I have verified connect rights to domain level same service account for both principle and mirror. 9. Earlier it is SQL server 2014 sp2 ,today I have updated with latest service sp3 even though still I can see same in mirror monitor Not connected to mirror. Please help on this issue, how to resolve this?