WinCC two Redundant HMI server not communicate - named connection show disconnected

Hello,

I hope you are all doing great.

I have redundant Siemens PLC S7 400 which connects with two HMI servers 

1. In the tag management under named connection I named my HMI like that T AER1-OP 1 and TAER2-OP1 
2. When I open program In HMI (TAER1-OP1) program run properly but in HMI (TAER2-OP1) open program it show disconnect status of connection. 
3. When I changed the name of HMI (TAER2-OP1) with (TAER1-OP1) HMI under connection parameter, it run program but same time HMI (TAER1-OP1) connection disconnected. 
4. However, I checked HMI (TAER2-OP1) status in station configuration editor where it show HMI in run mode. 

Please suggest solution steps for this issue and also guide more steps for troubleshooting.    

Please find attached picture of current status of disconnect connection. 

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