Balancing setup on BROCADE ADX 4000, how to optimize?

Question

Load balancing

Good afternoon, we encountered a problem in load balancing on brocade adx 4000. How to optimize?
Current configuration:

server virtual <i>server_name</i> <i>ip_address</i>
sticky-age 60                                                   
 sym-priority 200
predictor round-robin
port http sticky
bind http name_server02 20071 name_server02 20072 name_server02 20073 name_server02 20074
bind http name_server02 20075 name_server02 20076 name_server02 20077 name_server03 20071
bind http name_server03 20072 name_server03 20073 name_server03 20074 name_server03 20075
bind http name_server03 20076 name_server03 20077 name_server04 20071 name_server04 20072
bind http name_server04 20073 name_server04 20074 name_server04 20075 name_server04 20076
bind http name_server04 20077 name_server05 20071 name_server05 20072 name_server05 20073
bind http name_server05 20074 name_server05 20075 name_server05 20076 name_server05 20077

With this configuration, the load is not uniform, what could be the reason? Some ports have 500 connections, others zero.