This is not a "bug" per se, more like a lack of a feature.  I'm starting to use the zone assignments and I noticed that zones can only be created for indoor spaces.  If you assign all your staff to zones, the outdoor items may not be serviced.  For example, I have a donation station by the large outdoor artifact by the helipad in Passwater Cove.  When I assign all my security guards to zones I created, none of them will empty the donation station.  I can't even get it to be emptied if I use the "call security" button on the donation station.  Similarly, even if I pick up a security officer and place them next to the donation bin, they will walk away back to their zone without emptying.  

Although I understand the workaround is to not assign staff to any zone, this causes them to be free to roam the whole museum, decreasing efficiency.