clients and servers are on the same network

these are tricky things to trouble shoot via a forum, if you have a F5 partner or can contact support about it and have them have a look that would probably be quicker.

if you can't then i don't mind taking a stab. first can you show the packet capture (wireshark screenshot with the required columns shown) which shows the behaviour? point out your request from the client and the rest of the session.

this is mainly to determine the traffic you see if related to the request, it could be other traffic which confuses things. what is the default gateway for the client and the nodes?

have you tried with a virtual server with an IP in the range of the rest of the systems?

have you modified the virtual server settings from the defaults?