My load balancer don't balance...!

in one sentence, you wrote "1 Virtual server with Default Persistence Profile by default", in another one, you wrote "I don't defined a persistence profile"... Which one is correct? Sounds to me as if an persistence was configured which would explain the behaviour.

try using curl with --no-keepalives, otherwise it might make use of http session keepalive and issue many http requests over the same tcp connection (which will not get re-balanced by default unless oneconnect is configured).