Version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f54494e, type:
build date: 2019-07-29, 09:44 AM
I've found a Blender 2.8 manual typo in the chapter: Sculpting & Painting » Brush » Stroke » Curve Add Points.
Add Points Ctrl-LMB
You can define additional curve control points by using Ctrl-LMB. The handles can define by dragging the mouse before releasing the mouse button.
The key Ctrl-LMB is not adding points to the curve. It's the "Ctrl-RMB" key.
So either the manual is wrong or Blenders current application shortcut.