So here's the problem: with Evernote on my iPad Pro:
Start new note
Open Sketch / Draw to make note using Apple Pencil
iPad locks itself / goes into 'sleep'
Unlock iPad to find I'm back on homescreen and when I re-open Evernote, all my notes haven't been saved and have disappeared.
Not sure if this as Evernote / Apple / iOS feature request, but super annoying. Only way I've found to solve this is to hit 'Done' every 10 (or so) seconds to save my work.