Do you have 2 groups of AP+Client? To build P2P, you need to make sure AP and station face to each other and have clear line of sight. You can follow the FAQ to troubleshoot: 

https://www.tp-link.com/en/support/faq/2575/

Some issues may be resolved in new firmware. You can also update the firmware.

@Somnus 

Do you have 2 groups of AP+Client? To build P2P, you need to make sure AP and station face to each other and have clear line of sight. You can follow the FAQ to troubleshoot: 

https://www.tp-link.com/en/support/faq/2575/

Some issues may be resolved in new firmware. You can also update the firmware.

Thanks for the reply.

Yes i have a P2P connectivity, AP + Client. I have installed CCTV cameras at the location which are centralized through wireless (CPE220). Stations are connected at the camera site and all AP's are at the main centralized pole.

All pairs are connected with maximum strength, Signal quality is approx. Hor/Ver: -49/-54 (in between). 

Each station is containing 1 PTZ Camera, Whenever i try to add 2nd station on the same AP (which i at the main location), it connects successfully (strongly) but all network goes down. Ping response go form 3ms to 300ms, even 1000ms+. 

I had also upgraded the modules but the issue is still there.

Adding the cameras at the station side, Adding the new cpe200, causing the network unstable. There are only 4 cameras which have to connect wirelessly through cpe220.

Prompt response or remote support will be highly appreciated.

Thank you.