Okay, thanks zeddb.

My hardware is updated to the max (including nvidia drivers), so this is pretty much where we can go with MacOS 10.11.6. If Blender 2.8 is to be compatible with MacOS 10.11, these are the issues we'll be bumping into.
This was also an issue with 10.11.6 and Nvidia -> T62766: Eevee DOF cut plane.

In T62766#644883, @Sebastian Parborg (zeddb) wrote:

@Jari Aaltonen (jaalto) can you see if the problem still happens with Mojave?

Someone else had this problem a month ago with build 2019-02-12 here: https://blender.stackexchange.com/questions/132065/blender-2-8-eevee-depth-of-field-geometry-clipping-issue
Also using Mac OS X El Capitan, but the graphics card was different than mine.

Same problem here. Only one hair visible in viewport. Particle edit mode, all hairs visible okay. Switch to Cycles, still one hair visible on wireframe and solid view. But Cycles rendered view shows hairs. Eevee doesn't.

Restored to factory settings. The same occurs.

Thanks for the hair vector blur fix, Brecht.