There is a green icon in bottom right corner of Dorico’s main window. Its purpose is to show MIDI activity. If you plug your midi keyboard in (and turn it on, if that doesn’t happen automatically), does the green icon do anything if you play the keyboard? Does it do anything if you don’t play the keyboard?
Could the video engine (for the video JMSmordal was not able to attach) be slowing his version down beyond what Daniel is experiencing?
That normally manifests with higher than normal CPU usage, but it doesn’t cause operations like saving to stall, in our experience.