DNS Listener behavior

Hi Guys, 
I am testing a DNS listener with a DNS load balancing pool, when I do a query trough the listener It is not working. 

This is my enviroment: 

Listener IP: 10.1.10.52

Internal Self IP: 10.1.20.239 

DNS Server (pool member): 10.1.20.238

This is the curious thing, I opened a wireshark direcly on the server and saw this:

How is possible and why the F5 sent packets to the server looking for the listener instead of looking for the server IP? 

The DNS monitor works perfect, the F5 IP 239 reach server IP 238 and it responses back : 

Thank you!