Solving visual lag in Cubase 9?

I have a huge project going - about 12 minutes with lots of tracks. The audio plays back fine with no hiccups. However, the interface stutters and is so delayed that it’s hard to work. It takes about three seconds for a single click to register. Any thoughts on how to resolve this?

It is a known issue on macOS. The only solution for now is to use it on Windows.

I installed Mountain Lion which runs much more smoothly re GUI lag than El Capitan and Sierra/ High Sierra.