My MacPro has massive issues with Mojave 10.14.4 and latest parallels. Windows 10 has become unusable. I have the exact same setup on my MacBook Pro and it is fine. Seems to just effect a handful of Mac models, I had a old VMware Fusion license so I spun up a Windows 10 in that and it seems to work better than Parallels at the minute. Please fix this performance issue Parallels people, it's driving a lot of us insane.