Since the post actions menu overlays header etc it has had an impact on user notes on mobile. This is possible after pressing posts wrench and selecting add user note. However, if you press to write in it, post admin disappears bit it would be better without this look.
Confirmed, z-index is off here.
@awesomerobot can a designer have a look?
This was an issue in the plugin, apparently we need to set a secondary action as closing the menu, or in some cases the menu could not be closed (especially android).
Thanks for the report.