It would appear that the mouse actions are replayed only on the primary display in Ubuntu 16.04, regardless of where the recording took place or on which display the cursor currently exists.
From my experience, recording and replay work fine on multiple displays on Windows. I'll check on Ubuntu as soon as I have access to multiple displays on this OS.
It would appear that the mouse actions are replayed only on the primary display in Ubuntu 16.04, regardless of where the recording took place or on which display the cursor currently exists.