Brush/ Wacom Cintiq Problems Harmony 12.1.2

I’m having serious performance issues with the brush tool in Harmony 12. I’m getting lag when drawing on my Wacom cintiq 12WX. I’ve tested it in Harmony 10 and it’s fine, it only seems to be happening with v12. I’ve tried installing older drivers and reinstalling Harmony but no joy as of yet. I’m wondering if anyone has had similar issues?

These are my comps specs:
Mac: El Capitan Version 10.11.4
Processor: 3.1 GHz Intel Core i7
Memory: 16 GB 1600 MHz DDR3
Graphics: NVIDIA GeForce GT 650M 512 MB