Can't execute more then single user concurrent

Hello Gatling Experts.

I need to check process, that downloads (*.mp4) file from remote machine trans-code it and downloads it to my computer.
When I use CURL in loop - it works fine (.Same if I use several browsers(chrome,Firefox)

But if I use Gatling(2.1.5 with jdk1.8.60) only single user lunched .

Below is my flow and part of log.
I also changed allowPoolingConnections = false in my gatling.conf file
but in logs I still found " Connection: keep-alive" in header

Any Thoughts ?

import scala.concurrent.duration._
import io.gatling.core.Predef._
import io.gatling.http.Predef._
import io.gatling.jdbc.Predef._
import io.gatling.core.feeder.RecordSeqFeederBuilder
import java.util.UUID

class LoadTest extends Simulation{

val basehostUrL=""“"”"

val httpProtocol = http
.userAgentHeader(""“Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.124 Safari/537.36"”")


val action = http(“get file”)

val loadhttpGroups = group(“Load Flow”) {
during(2 minutes) {
val loadFlow = scenario(“Load Flow”).exec(loadhttpGroups)

setUp(loadFlow.inject(rampUsers(5) over(5 seconds)).protocols(httpProtocol))

Despite the fact that I erased Cookies and httpCache with ( exec(flushSessionCookies).exec(flushCookieJar).exec(flushHttpCache))
in log could be seen for each request same value of Cookie: connect.sid
Simulation starts with only one user ,not 5 as injected in setup…

In order to eliminate issue of single thread response, I executed 5 requests in parallel (with same generated Cookie: connect.sid=…)
using Fiddler Composer
The server responded parallel…

Did you try upgrading Gatling version?
Can you share a reproducer?

Hello Stéphane
Thanks for response.
I upgraded my gatling from 2.1.5 to 2.1.7 - nothing changed -simulation still injects only one user
I"ll share reproducer via email.