Global configuration is only taken in account when the Jenkins instance is restarted?
Did you restart after changing your global configuration?

I eventually did, but I find this behavior unfriendly and not intuitive. In this particular situation I could not restart Jenkins at once, since there were other jobs building, some of them run for many hours. So in case I could not restart Jenkins instance, I also could not build another job which relied on global configuration. Built-in variable setting does not work that way and does not require Jenkins restart after changing global configuration.

I'm afraid I can't fix your issue. With the current Jenkins infrastructure, there is a need to restart for doing these EnvInject features.
Therefore, could we close the issue?
Thanks

Any update?
What is your opinion?

Is it possible to help me?

If this is blocked by Jenkins core, I think it would be better to retarget this issue to core. Restarting Jenkins instance is an expensive operation and until new configuration is applied some of the builds are failing. I find such behavior unacceptable.

Re-target to core to find if there is a solution?

There is no description in this issue, about what doesn't work or what should be improved in core.
So this issue is much incomplete.
Reassigning to envinject for that reason.