Pen Pressure for Adobe Illustrator in Mojave
If you are using Astropad with Illustrator while running macOS Mojave (10.14), you will need to enable Automation for Illustrator.
During Illustrator's startup, you should receive an initial prompt to access System Preferences after a Wacom driver has been installed on your Mac.
This permission only appears when a Wacom Driver is installed. When these permissions are denied, pen input and pressure sensitivity will be disabled.
If you never received a prompt or accidentally selected “Don’t Allow,” you can still manually enable this permission: