Simulation Not Reaching Target TPS

We have a simulation where we try to achieve a certain throughput on a rest endpoint by injecting a constant amount of users per second. What we observe is that the simulation is not able to inject that many users per second and our target throughput is not reached.

`
scenario.inject(constantUsersPerSec(1000) during testDuration).throttle(jumpToRps(200), holdFor(testDuration))

`

However, when we instead have a simulation with multiple of the same scenario with a lower number of users injected per second we are able to achieve the desired throughput.

`

setUp(
scenario.inject(constantUsersPerSec(250) during testDuration).throttle(jumpToRps(200), holdFor(testDuration)),
scenario.inject(constantUsersPerSec(250) during testDuration).throttle(jumpToRps(200), holdFor(testDuration)),
scenario.inject(constantUsersPerSec(250) during testDuration).throttle(jumpToRps(200), holdFor(testDuration)),
scenario.inject(constantUsersPerSec(250) during testDuration).throttle(jumpToRps(200), holdFor(testDuration))
)

`

We have shared connections enabled in our http protocol configuration.

What factors could cause this and are there any properties we can configure to achieve the desire throughput with only one scenario?

Thanks,
Michael