Headless Linux build 100% CPU usage 2019 vs 10% 2018

So I create two projects, one in Unity 2019.1.8f1 and one in Unity 2018.3.9f1. I have a script that builds the projects and deploys them to the server, the script is copied on both projects so it’s the same. Here is the code that builds it:

BuildPipeline.BuildPlayer(serverScenes, config.BuildPath + "/" + config.BuildFileName + ".x86_64", BuildTarget.StandaloneLinux64, BuildOptions.EnableHeadlessMode);

2019.1.8f1 runs at 100% CPU usage while 2018.3.9f1 runs at 10% CPU usage.

Any idea what changed with Unity that could cause such a discrepancy?

Maybe you can try setting the target framerate.

https://issuetracker.unity3d.com/issues/network-manager-has-increased-cpu-usage-in-linux-player-after-upgrade-to-2018-dot-2

https://forum.unity.com/threads/headless-server-high-cpu-usage.441727/