The http monitor check failed

I have a pool, the pool which has two pool member, I use the http monitor check pool member. The result is a failure.

 

note：The two pool members share a http monitor

 

for example：

 

pool member 1: 192.168.3.117:80

 

pool member 2: 192.168.3.217:80

 

Send String : GET / HTTP/1.1\r\nConnection: close\r\n Receive String : 200

 

Who can help me ？ thank you very much !