I think I’m having the same issue. It runs fine on my older 2013 i5 imac and is choppy and sluggish on my 2015 i7. One difference is I have Mojave version 10.14.5 on older (smoother running FMOD) and I have Mojave 10.14.6 on my newer iMac (slow, using 110% CPU on activity monitor). Not sure if that is the issue. Any info on this issue is appreciated!