I have an issue where rotation keeps freezing up as soon as I hit the ALT key. It will either lock permanently or put me in a mode where I can only rotate 45 degrees at a time. I have never seen this happen before- I even uninstalled an re-installed 2019 and it is still giving me this issue. When this happens the normal cmd-N does not work to refresh the scene and I have to close Zbrush. However, every time I open Zbrush the same thing happens as soon as I import a model. Is there a setting on causing this? i have tried resetting preferences to no avail. Is that a Mac specific issue?