Bad App performance.

I have 8 voices running in a short re-arrangement (only 8 measures) of parts to better fit beginning players. Whether I'm navigating through parts, programming parts, or using playback the app is performing abysmally and tanking the CPU usage on my computer and causing significant lag and somehow sound tearing as well. Tried reinstalling and that did not fix the issue. Not sure what is causing this as I'm not sure if there was any issue in the previous patch of 4.0.

(On version 4.0.1)