Yes, even I am facing this Mouse Freeze problem when I boot up. It only lasts for 40 seconds everytime and goes away. After doing some research, I think this problem has something to do with external display and UHD 630. This doesn't happen when using a dedicated gpu. This is more of an Apple issue, than a hackintosh issue. It's all good, just need to wait 40 secs after boot up to get it working normally.