rampUp users is not starting all of them

I have a legacy simulation that rampUp 50K user over 3 minutes

myScenario.inject(rampUsers(50000) over 3.minutes)

after 3 minutes only 49995 users are in active and 5 stay in wait until the end of the simulations, however if I run the same simulation ramping up over any of 1, 2, 5, 7, 12 minutes all the user ramp up over the selected period. I have the same error in 9 adn 15 minutes but in this case 50 users remain in wait, My scenario looks like:

val myScenario = scenario(“SimpleScenario 3min”)
.feed(Iterator(feeder).flatten)
.exec(SomeActionBuilder("${col1}"))

setUp(myScenario.inject(rampUsers(50000) over 3.minutes))

.protocols(someProtocol)

Gatling version ? Can you reproduce with 3.7.4?