Unity Server (standalone) hangs on startup (Mac and Linux Build)

I'm having an issue with server builds. What's also confusing is that the log indicates that enlighten is starting up regardless of whether it's a server build (even if I pass

-nographics

and

-batchmode

flag).

macOS 10.4.4

Code (CSharp):

1. Mono path[0] = '/Volumes/Wolverine/Projects/TestServer/Builds/Mac/test_server.app/Contents/Resources/Data/Managed'
2. Mono config path = '/Volumes/Wolverine/Projects/TestServer/Builds/Mac/test_server.app/Contents/MonoBleedingEdge/etc'
3. Initialize engine version: 2019.1.0f2 (292b93d75a2c)
4. Forcing GfxDevice: Null
5. GfxDevice: creating device client; threaded=0
6. NullGfxDevice:
7.     Version:  NULL 1.0 [1.0]
8.     Renderer: Null Device
9.     Vendor:   Unity Technologies
10. Begin MonoManager ReloadAssembly
11. - Completed reload, in  0.096 seconds
12. UnloadTime: 0.878352 ms
13. Running in headless mode
14. (Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 48)
15.  
16. Setting up 4 worker threads for Enlighten.
17.   Thread -> id: 700009e32000 -> priority: 1
18.   Thread -> id: 700009eb5000 -> priority: 1
19.   Thread -> id: 700009fbb000 -> priority: 1
20.   Thread -> id: 700009f38000 -> priority: 1
21.  

On Ubuntu 18 it does the same thing but hangs after a single worker thread (most likely because it's a VM with a "single processor").

How do I go about debugging this?