I figured out what's going on, some of the ground sprites are on the "Non-Layout" layer. I'm unsure how they would get there, I can't reproduce it.
The only way to access those objects is by events.
Do this to see them all:
+ System: Start of layout
-> Ground: Move to layer 1
Or just add this event to get rid of them:
+ Ground: Is on layer "Non-Layout"
-> Ground: Destroy