Overlapped Networks Question

I have two networks which overlaps.

• 10.140.10.0/28 and 10.240.20.0/28  in  "DC_Networks"
• 10.140.10.0/23 and 10.240.20.0/23  in  "DRC_Networks"

An iRule is using to determine which DNS response should be returned and it looks source IP address while deciding. The answer is different for small and big network blocks.

when DNS_REQUEST {
    set qname [string tolower [DNS::question name]]
    log local0. "DNS Query: $qname"
    if { [class match $qname equals /Common/backend_services_dg] && [DNS::question type] == "A" } {
        DNS::answer clear
        if { [class match [IP::client_addr] equals "/Common/DC_Networks"] } {
            DNS::answer insert "${qname}. 111 [DNS::question class] [DNS::question type] [getfield [class match -value $qname equals /Common/backend_services_dg] ":" 1]"
            log local0. "DEBUG1:  Query: $qname,  Src IP: [IP::client_addr]"
        } elseif { [class match [IP::client_addr] equals "/Common/DRC_Networks"] } {
            DNS::answer insert "${qname}. 112 [DNS::question class] [DNS::question type] [getfield [class match -value $qname equals /Common/backend_services_dg] ":" 2]"
            log local0. "DEBUG2:  Query: $qname,  Src IP: [IP::client_addr]"
        } else {
            DNS::answer insert "${qname}. 113 [DNS::question class] [DNS::question type] [getfield [class match -value $qname equals /Common/backend_services_dg] ":" 1]"
            log local0. "DEBUG3:  Query: $qname,  Src IP: [IP::client_addr]"
        }
        DNS::return
    }
}

 Small network blocks listed in "DC_Networks" and bigger networks are listed in "DRC_Networks".  Before making some tests, i was certain i will see two log lines which starts with "DEBUG" key word because, "if" and "elseif" compares each time for same condition, right?

While testing with "atmoptimizer.spc.com" i saw that the "elseif" never triggered for overlapped networks. I was expecting to see two DEBUG lines in logs for each query.

ltm data-group internal backend_services_dg {
    records {
        atmoptimizer.spc.com {
            data 192.168.1.100:10.10.12.100
        }
    }
}