Just for the record, I have very similar experience on my MacBookPro2017 running Mojave. I have recently reported this as a bug. The odd thing is that the first time, when I create a new project (desktop, no starter content) everytyhing works fine with no freezes, lockups etc. But when I open the same project again, the locks ups and freezes begin. Even the pointer locks on screen. I never seen any other software even being able to lock the system on this level.